- 26 5月, 2019 1 次提交
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由 Vitaly Kuznetsov 提交于
[ Upstream commit da66761c2d93a46270d69001abb5692717495a68 ] It was reported that with some special Multi Processor Group configuration, e.g: bcdedit.exe /set groupsize 1 bcdedit.exe /set maxgroup on bcdedit.exe /set groupaware on for a 16-vCPU guest WS2012 shows BSOD on boot when PV TLB flush mechanism is in use. Tracing kvm_hv_flush_tlb immediately reveals the issue: kvm_hv_flush_tlb: processor_mask 0x0 address_space 0x0 flags 0x2 The only flag set in this request is HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES, however, processor_mask is 0x0 and no HV_FLUSH_ALL_PROCESSORS is specified. We don't flush anything and apparently it's not what Windows expects. TLFS doesn't say anything about such requests and newer Windows versions seem to be unaffected. This all feels like a WS2012 bug, which is, however, easy to workaround in KVM: let's flush everything when we see an empty flush request, over-flushing doesn't hurt. Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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- 22 5月, 2019 2 次提交
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由 Sean Christopherson 提交于
commit ee66e453db13d4837a0dcf9d43efa7a88603161b upstream. ...now that VMX's preemption timer, i.e. the hv_timer, also adjusts its programmed time based on lapic_timer_advance_ns. Without the delay, a guest can see a timer interrupt arrive before the requested time when KVM is using the hv_timer to emulate the guest's interrupt. Fixes: c5ce8235 ("KVM: VMX: Optimize tscdeadline timer latency") Cc: <stable@vger.kernel.org> Cc: Wanpeng Li <wanpengli@tencent.com> Reviewed-by: NLiran Alon <liran.alon@oracle.com> Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Sean Christopherson 提交于
commit 11988499e62b310f3bf6f6d0a807a06d3f9ccc96 upstream. KVM allows userspace to violate consistency checks related to the guest's CPUID model to some degree. Generally speaking, userspace has carte blanche when it comes to guest state so long as jamming invalid state won't negatively affect the host. Currently this is seems to be a non-issue as most of the interesting EFER checks are missing, e.g. NX and LME, but those will be added shortly. Proactively exempt userspace from the CPUID checks so as not to break userspace. Note, the efer_reserved_bits check still applies to userspace writes as that mask reflects the host's capabilities, e.g. KVM shouldn't allow a guest to run with NX=1 if it has been disabled in the host. Fixes: d8017474 ("KVM: SVM: Only allow setting of EFER_SVME when CPUID SVM is set") Cc: stable@vger.kernel.org Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 17 5月, 2019 2 次提交
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由 Vitaly Kuznetsov 提交于
[ Upstream commit 7a223e06b1a411cef6c4cd7a9b9a33c8d225b10e ] In __apic_accept_irq() interface trig_mode is int and actually on some code paths it is set above u8: kvm_apic_set_irq() extracts it from 'struct kvm_lapic_irq' where trig_mode is u16. This is done on purpose as e.g. kvm_set_msi_irq() sets it to (1 << 15) & e->msi.data kvm_apic_local_deliver sets it to reg & (1 << 15). Fix the immediate issue by making 'tm' into u16. We may also want to adjust __apic_accept_irq() interface and use proper sizes for vector, level, trig_mode but this is not urgent. Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Paolo Bonzini 提交于
[ Upstream commit 1d487e9bf8ba66a7174c56a0029c54b1eca8f99c ] These were found with smatch, and then generalized when applicable. Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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- 15 5月, 2019 4 次提交
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由 Thomas Gleixner 提交于
commit 65fd4cb65b2dad97feb8330b6690445910b56d6a upstream Move L!TF to a separate directory so the MDS stuff can be added at the side. Otherwise the all hardware vulnerabilites have their own top level entry. Should have done that right away. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: NJon Masters <jcm@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Thomas Gleixner 提交于
commit 650b68a0622f933444a6d66936abb3103029413b upstream CPUs which are affected by L1TF and MDS mitigate MDS with the L1D Flush on VMENTER when updated microcode is installed. If a CPU is not affected by L1TF or if the L1D Flush is not in use, then MDS mitigation needs to be invoked explicitly. For these cases, follow the host mitigation state and invoke the MDS mitigation before VMENTER. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: NFrederic Weisbecker <frederic@kernel.org> Reviewed-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NJon Masters <jcm@redhat.com> Tested-by: NJon Masters <jcm@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Andi Kleen 提交于
commit 6c4dbbd14730c43f4ed808a9c42ca41625925c22 upstream X86_FEATURE_MD_CLEAR is a new CPUID bit which is set when microcode provides the mechanism to invoke a flush of various exploitable CPU buffers by invoking the VERW instruction. Hand it through to guests so they can adjust their mitigations. This also requires corresponding qemu changes, which are available separately. [ tglx: Massaged changelog ] Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: NFrederic Weisbecker <frederic@kernel.org> Reviewed-by: NJon Masters <jcm@redhat.com> Tested-by: NJon Masters <jcm@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Eduardo Habkost 提交于
commit d7b09c827a6cf291f66637a36f46928dd1423184 upstream Months ago, we have added code to allow direct access to MSR_IA32_SPEC_CTRL to the guest, which makes STIBP available to guests. This was implemented by commits d28b387f ("KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL") and b2ac58f9 ("KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL"). However, we never updated GET_SUPPORTED_CPUID to let userspace know that STIBP can be enabled in CPUID. Fix that by updating kvm_cpuid_8000_0008_ebx_x86_features and kvm_cpuid_7_0_edx_x86_features. Signed-off-by: NEduardo Habkost <ehabkost@redhat.com> Reviewed-by: NJim Mattson <jmattson@google.com> Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 08 5月, 2019 1 次提交
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由 David Rientjes 提交于
[ Upstream commit b86bc2858b389255cd44555ce4b1e427b2b770c0 ] This ensures that the address and length provided to DBG_DECRYPT and DBG_ENCRYPT do not cause an overflow. At the same time, pass the actual number of pages pinned in memory to sev_unpin_memory() as a cleanup. Reported-by: NCfir Cohen <cfir@google.com> Signed-off-by: NDavid Rientjes <rientjes@google.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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- 05 5月, 2019 2 次提交
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由 Jim Mattson 提交于
commit e8ab8d24b488632d07ce5ddb261f1d454114415b upstream. The size checks in vmx_nested_state are wrong because the calculations are made based on the size of a pointer to a struct kvm_nested_state rather than the size of a struct kvm_nested_state. Reported-by: NFelix Wilhelm <fwilhelm@google.com> Signed-off-by: NJim Mattson <jmattson@google.com> Reviewed-by: NDrew Schmitt <dasch@google.com> Reviewed-by: NMarc Orr <marcorr@google.com> Reviewed-by: NPeter Shier <pshier@google.com> Reviewed-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com> Fixes: 8fcc4b59 Cc: stable@ver.kernel.org Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Sean Christopherson 提交于
commit 8764ed55c9705e426d889ff16c26f398bba70b9b upstream. KVM's recent bug fix to update %rip after emulating I/O broke userspace that relied on the previous behavior of incrementing %rip prior to exiting to userspace. When running a Windows XP guest on AMD hardware, Qemu may patch "OUT 0x7E" instructions in reaction to the OUT itself. Because KVM's old behavior was to increment %rip before exiting to userspace to handle the I/O, Qemu manually adjusted %rip to account for the OUT instruction. Arguably this is a userspace bug as KVM requires userspace to re-enter the kernel to complete instruction emulation before taking any other actions. That being said, this is a bit of a grey area and breaking userspace that has worked for many years is bad. Pre-increment %rip on OUT to port 0x7e before exiting to userspace to hack around the issue. Fixes: 45def77ebf79e ("KVM: x86: update %rip after emulating IO") Reported-by: NSimon Becherer <simon@becherer.de> Reported-and-tested-by: NIakov Karpov <srid@rkmail.ru> Reported-by: NGabriele Balducci <balducci@units.it> Reported-by: NAntti Antinoja <reader@fennosys.fi> Cc: stable@vger.kernel.org Cc: Takashi Iwai <tiwai@suse.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 27 4月, 2019 3 次提交
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由 Suthikulpanit, Suravee 提交于
commit 4a58038b9e420276157785afa0a0bbb4b9bc2265 upstream. This reverts commit bb218fbcfaaa3b115d4cd7a43c0ca164f3a96e57. As Oren Twaig pointed out the old discussion: https://patchwork.kernel.org/patch/8292231/ that the change coud potentially cause an extra IPI to be sent to the destination vcpu because the AVIC hardware already set the IRR bit before the incomplete IPI #VMEXIT with id=1 (target vcpu is not running). Since writting to ICR and ICR2 will also set the IRR. If something triggers the destination vcpu to get scheduled before the emulation finishes, then this could result in an additional IPI. Also, the issue mentioned in the commit bb218fbcfaaa was misdiagnosed. Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Reported-by: NOren Twaig <oren@scalemp.com> Signed-off-by: NSuravee Suthikulpanit <suravee.suthikulpanit@amd.com> Cc: stable@vger.kernel.org Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Vitaly Kuznetsov 提交于
commit 99c221796a810055974b54c02e8f53297e48d146 upstream. I noticed that apic test from kvm-unit-tests always hangs on my EPYC 7401P, the hanging test nmi-after-sti is trying to deliver 30000 NMIs and tracing shows that we're sometimes able to deliver a few but never all. When we're trying to inject an NMI we may fail to do so immediately for various reasons, however, we still need to inject it so enable_nmi_window() arms nmi_singlestep mode. #DB occurs as expected, but we're not checking for pending NMIs before entering the guest and unless there's a different event to process, the NMI will never get delivered. Make KVM_REQ_EVENT request on the vCPU from db_interception() to make sure pending NMIs are checked and possibly injected. Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Sean Christopherson 提交于
commit 8f4dc2e77cdfaf7e644ef29693fa229db29ee1de upstream. Neither AMD nor Intel CPUs have an EFER field in the legacy SMRAM save state area, i.e. don't save/restore EFER across SMM transitions. KVM somewhat models this, e.g. doesn't clear EFER on entry to SMM if the guest doesn't support long mode. But during RSM, KVM unconditionally clears EFER so that it can get back to pure 32-bit mode in order to start loading CRs with their actual non-SMM values. Clear EFER only when it will be written when loading the non-SMM state so as to preserve bits that can theoretically be set on 32-bit vCPUs, e.g. KVM always emulates EFER_SCE. And because CR4.PAE is cleared only to play nice with EFER, wrap that code in the long mode check as well. Note, this may result in a compiler warning about cr4 being consumed uninitialized. Re-read CR4 even though it's technically unnecessary, as doing so allows for more readable code and RSM emulation is not a performance critical path. Fixes: 660a5d51 ("KVM: x86: save/load state on SMM switch") Cc: stable@vger.kernel.org Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 20 4月, 2019 1 次提交
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由 Sean Christopherson 提交于
[ Upstream commit bd18bffca35397214ae68d85cf7203aca25c3c1d ] A VMEnter that VMFails (as opposed to VMExits) does not touch host state beyond registers that are explicitly noted in the VMFail path, e.g. EFLAGS. Host state does not need to be loaded because VMFail is only signaled for consistency checks that occur before the CPU starts to load guest state, i.e. there is no need to restore any state as nothing has been modified. But in the case where a VMFail is detected by hardware and not by KVM (due to deferring consistency checks to hardware), KVM has already loaded some amount of guest state. Luckily, "loaded" only means loaded to KVM's software model, i.e. vmcs01 has not been modified. So, unwind our software model to the pre-VMEntry host state. Not restoring host state in this VMFail path leads to a variety of failures because we end up with stale data in vcpu->arch, e.g. CR0, CR4, EFER, etc... will all be out of sync relative to vmcs01. Any significant delta in the stale data is all but guaranteed to crash L1, e.g. emulation of SMEP, SMAP, UMIP, WP, etc... will be wrong. An alternative to this "soft" reload would be to load host state from vmcs12 as if we triggered a VMExit (as opposed to VMFail), but that is wildly inconsistent with respect to the VMX architecture, e.g. an L1 VMM with separate VMExit and VMFail paths would explode. Note that this approach does not mean KVM is 100% accurate with respect to VMX hardware behavior, even at an architectural level (the exact order of consistency checks is microarchitecture specific). But 100% emulation accuracy isn't the goal (with this patch), rather the goal is to be consistent in the information delivered to L1, e.g. a VMExit should not fall-through VMENTER, and a VMFail should not jump to HOST_RIP. This technically reverts commit "5af41573 (KVM: nVMX: Fix mmu context after VMLAUNCH/VMRESUME failure)", but retains the core aspects of that patch, just in an open coded form due to the need to pull state from vmcs01 instead of vmcs12. Restoring host state resolves a variety of issues introduced by commit "4f350c6d (kvm: nVMX: Handle deferred early VMLAUNCH/VMRESUME failure properly)", which remedied the incorrect behavior of treating VMFail like VMExit but in doing so neglected to restore arch state that had been modified prior to attempting nested VMEnter. A sample failure that occurs due to stale vcpu.arch state is a fault of some form while emulating an LGDT (due to emulated UMIP) from L1 after a failed VMEntry to L3, in this case when running the KVM unit test test_tpr_threshold_values in L1. L0 also hits a WARN in this case due to a stale arch.cr4.UMIP. L1: BUG: unable to handle kernel paging request at ffffc90000663b9e PGD 276512067 P4D 276512067 PUD 276513067 PMD 274efa067 PTE 8000000271de2163 Oops: 0009 [#1] SMP CPU: 5 PID: 12495 Comm: qemu-system-x86 Tainted: G W 4.18.0-rc2+ #2 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:native_load_gdt+0x0/0x10 ... Call Trace: load_fixmap_gdt+0x22/0x30 __vmx_load_host_state+0x10e/0x1c0 [kvm_intel] vmx_switch_vmcs+0x2d/0x50 [kvm_intel] nested_vmx_vmexit+0x222/0x9c0 [kvm_intel] vmx_handle_exit+0x246/0x15a0 [kvm_intel] kvm_arch_vcpu_ioctl_run+0x850/0x1830 [kvm] kvm_vcpu_ioctl+0x3a1/0x5c0 [kvm] do_vfs_ioctl+0x9f/0x600 ksys_ioctl+0x66/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x4f/0x100 entry_SYSCALL_64_after_hwframe+0x44/0xa9 L0: WARNING: CPU: 2 PID: 3529 at arch/x86/kvm/vmx.c:6618 handle_desc+0x28/0x30 [kvm_intel] ... CPU: 2 PID: 3529 Comm: qemu-system-x86 Not tainted 4.17.2-coffee+ #76 Hardware name: Intel Corporation Kabylake Client platform/KBL S RIP: 0010:handle_desc+0x28/0x30 [kvm_intel] ... Call Trace: kvm_arch_vcpu_ioctl_run+0x863/0x1840 [kvm] kvm_vcpu_ioctl+0x3a1/0x5c0 [kvm] do_vfs_ioctl+0x9f/0x5e0 ksys_ioctl+0x66/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x49/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 5af41573 (KVM: nVMX: Fix mmu context after VMLAUNCH/VMRESUME failure) Fixes: 4f350c6d (kvm: nVMX: Handle deferred early VMLAUNCH/VMRESUME failure properly) Cc: Jim Mattson <jmattson@google.com> Cc: Krish Sadhukhan <krish.sadhukhan@oracle.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <rkrcmar@redhat.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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- 17 4月, 2019 4 次提交
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由 Marc Orr 提交于
commit c73f4c998e1fd4249b9edfa39e23f4fda2b9b041 upstream. Referring to the "VIRTUALIZING MSR-BASED APIC ACCESSES" chapter of the SDM, when "virtualize x2APIC mode" is 1 and "APIC-register virtualization" is 0, a RDMSR of 808H should return the VTPR from the virtual APIC page. However, for nested, KVM currently fails to disable the read intercept for this MSR. This means that a RDMSR exit takes precedence over "virtualize x2APIC mode", and KVM passes through L1's TPR to L2, instead of sourcing the value from L2's virtual APIC page. This patch fixes the issue by disabling the read intercept, in VMCS02, for the VTPR when "APIC-register virtualization" is 0. The issue described above and fix prescribed here, were verified with a related patch in kvm-unit-tests titled "Test VMX's virtualize x2APIC mode w/ nested". Signed-off-by: NMarc Orr <marcorr@google.com> Reviewed-by: NJim Mattson <jmattson@google.com> Fixes: c992384b ("KVM: vmx: speed up MSR bitmap merge") Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Marc Orr 提交于
commit acff78477b9b4f26ecdf65733a4ed77fe837e9dc upstream. The nested_vmx_prepare_msr_bitmap() function doesn't directly guard the x2APIC MSR intercepts with the "virtualize x2APIC mode" MSR. As a result, we discovered the potential for a buggy or malicious L1 to get access to L0's x2APIC MSRs, via an L2, as follows. 1. L1 executes WRMSR(IA32_SPEC_CTRL, 1). This causes the spec_ctrl variable, in nested_vmx_prepare_msr_bitmap() to become true. 2. L1 disables "virtualize x2APIC mode" in VMCS12. 3. L1 enables "APIC-register virtualization" in VMCS12. Now, KVM will set VMCS02's x2APIC MSR intercepts from VMCS12, and then set "virtualize x2APIC mode" to 0 in VMCS02. Oops. This patch closes the leak by explicitly guarding VMCS02's x2APIC MSR intercepts with VMCS12's "virtualize x2APIC mode" control. The scenario outlined above and fix prescribed here, were verified with a related patch in kvm-unit-tests titled "Add leak scenario to virt_x2apic_mode_test". Note, it looks like this issue may have been introduced inadvertently during a merge---see 15303ba5. Signed-off-by: NMarc Orr <marcorr@google.com> Reviewed-by: NJim Mattson <jmattson@google.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 David Rientjes 提交于
commit ede885ecb2cdf8a8dd5367702e3d964ec846a2d5 upstream. get_num_contig_pages() could potentially overflow int so make its type consistent with its usage. Reported-by: NCfir Cohen <cfir@google.com> Cc: stable@vger.kernel.org Signed-off-by: NDavid Rientjes <rientjes@google.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Jim Mattson 提交于
[ Upstream commit 9ebdfe5230f2e50e3ba05c57723a06e90946815a ] According to the SDM, "NMI-window exiting" VM-exits wake a logical processor from the same inactive states as would an NMI and "interrupt-window exiting" VM-exits wake a logical processor from the same inactive states as would an external interrupt. Specifically, they wake a logical processor from the shutdown state and from the states entered using the HLT and MWAIT instructions. Fixes: 6dfacadd ("KVM: nVMX: Add support for activity state HLT") Signed-off-by: NJim Mattson <jmattson@google.com> Reviewed-by: NPeter Shier <pshier@google.com> Suggested-by: NSean Christopherson <sean.j.christopherson@intel.com> [Squashed comments of two Jim's patches and used the simplified code hunk provided by Sean. - Radim] Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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- 03 4月, 2019 2 次提交
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由 Sean Christopherson 提交于
commit 0cf9135b773bf32fba9dd8e6699c1b331ee4b749 upstream. The CPUID flag ARCH_CAPABILITIES is unconditioinally exposed to host userspace for all x86 hosts, i.e. KVM advertises ARCH_CAPABILITIES regardless of hardware support under the pretense that KVM fully emulates MSR_IA32_ARCH_CAPABILITIES. Unfortunately, only VMX hosts handle accesses to MSR_IA32_ARCH_CAPABILITIES (despite KVM_GET_MSRS also reporting MSR_IA32_ARCH_CAPABILITIES for all hosts). Move the MSR_IA32_ARCH_CAPABILITIES handling to common x86 code so that it's emulated on AMD hosts. Fixes: 1eaafe91 ("kvm: x86: IA32_ARCH_CAPABILITIES is always supported") Cc: stable@vger.kernel.org Reported-by: NXiaoyao Li <xiaoyao.li@linux.intel.com> Cc: Jim Mattson <jmattson@google.com> Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Sean Christopherson 提交于
commit 45def77ebf79e2e8942b89ed79294d97ce914fa0 upstream. Most (all?) x86 platforms provide a port IO based reset mechanism, e.g. OUT 92h or CF9h. Userspace may emulate said mechanism, i.e. reset a vCPU in response to KVM_EXIT_IO, without explicitly announcing to KVM that it is doing a reset, e.g. Qemu jams vCPU state and resumes running. To avoid corruping %rip after such a reset, commit 0967b7bf ("KVM: Skip pio instruction when it is emulated, not executed") changed the behavior of PIO handlers, i.e. today's "fast" PIO handling to skip the instruction prior to exiting to userspace. Full emulation doesn't need such tricks becase re-emulating the instruction will naturally handle %rip being changed to point at the reset vector. Updating %rip prior to executing to userspace has several drawbacks: - Userspace sees the wrong %rip on the exit, e.g. if PIO emulation fails it will likely yell about the wrong address. - Single step exits to userspace for are effectively dropped as KVM_EXIT_DEBUG is overwritten with KVM_EXIT_IO. - Behavior of PIO emulation is different depending on whether it goes down the fast path or the slow path. Rather than skip the PIO instruction before exiting to userspace, snapshot the linear %rip and cancel PIO completion if the current value does not match the snapshot. For a 64-bit vCPU, i.e. the most common scenario, the snapshot and comparison has negligible overhead as VMCS.GUEST_RIP will be cached regardless, i.e. there is no extra VMREAD in this case. All other alternatives to snapshotting the linear %rip that don't rely on an explicit reset announcenment suffer from one corner case or another. For example, canceling PIO completion on any write to %rip fails if userspace does a save/restore of %rip, and attempting to avoid that issue by canceling PIO only if %rip changed then fails if PIO collides with the reset %rip. Attempting to zero in on the exact reset vector won't work for APs, which means adding more hooks such as the vCPU's MP_STATE, and so on and so forth. Checking for a linear %rip match technically suffers from corner cases, e.g. userspace could theoretically rewrite the underlying code page and expect a different instruction to execute, or the guest hardcodes a PIO reset at 0xfffffff0, but those are far, far outside of what can be considered normal operation. Fixes: 432baf60 ("KVM: VMX: use kvm_fast_pio_in for handling IN I/O") Cc: <stable@vger.kernel.org> Reported-by: NJim Mattson <jmattson@google.com> Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 24 3月, 2019 6 次提交
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由 Sean Christopherson 提交于
commit 34333cc6c2cb021662fd32e24e618d1b86de95bf upstream. Regarding segments with a limit==0xffffffff, the SDM officially states: When the effective limit is FFFFFFFFH (4 GBytes), these accesses may or may not cause the indicated exceptions. Behavior is implementation-specific and may vary from one execution to another. In practice, all CPUs that support VMX ignore limit checks for "flat segments", i.e. an expand-up data or code segment with base=0 and limit=0xffffffff. This is subtly different than wrapping the effective address calculation based on the address size, as the flat segment behavior also applies to accesses that would wrap the 4g boundary, e.g. a 4-byte access starting at 0xffffffff will access linear addresses 0xffffffff, 0x0, 0x1 and 0x2. Fixes: f9eb4af6 ("KVM: nVMX: VMX instructions: add checks for #GP/#SS exceptions") Cc: stable@vger.kernel.org Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Sean Christopherson 提交于
commit 8570f9e881e3fde98801bb3a47eef84dd934d405 upstream. The address size of an instruction affects the effective address, not the virtual/linear address. The final address may still be truncated, e.g. to 32-bits outside of long mode, but that happens irrespective of the address size, e.g. a 32-bit address size can yield a 64-bit virtual address when using FS/GS with a non-zero base. Fixes: 064aea77 ("KVM: nVMX: Decoding memory operands of VMX instructions") Cc: stable@vger.kernel.org Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Sean Christopherson 提交于
commit 946c522b603f281195af1df91837a1d4d1eb3bc9 upstream. The VMCS.EXIT_QUALIFCATION field reports the displacements of memory operands for various instructions, including VMX instructions, as a naturally sized unsigned value, but masks the value by the addr size, e.g. given a ModRM encoded as -0x28(%ebp), the -0x28 displacement is reported as 0xffffffd8 for a 32-bit address size. Despite some weird wording regarding sign extension, the SDM explicitly states that bits beyond the instructions address size are undefined: In all cases, bits of this field beyond the instruction’s address size are undefined. Failure to sign extend the displacement results in KVM incorrectly treating a negative displacement as a large positive displacement when the address size of the VMX instruction is smaller than KVM's native size, e.g. a 32-bit address size on a 64-bit KVM. The very original decoding, added by commit 064aea77 ("KVM: nVMX: Decoding memory operands of VMX instructions"), sort of modeled sign extension by truncating the final virtual/linear address for a 32-bit address size. I.e. it messed up the effective address but made it work by adjusting the final address. When segmentation checks were added, the truncation logic was kept as-is and no sign extension logic was introduced. In other words, it kept calculating the wrong effective address while mostly generating the correct virtual/linear address. As the effective address is what's used in the segment limit checks, this results in KVM incorreclty injecting #GP/#SS faults due to non-existent segment violations when a nested VMM uses negative displacements with an address size smaller than KVM's native address size. Using the -0x28(%ebp) example, an EBP value of 0x1000 will result in KVM using 0x100000fd8 as the effective address when checking for a segment limit violation. This causes a 100% failure rate when running a 32-bit KVM build as L1 on top of a 64-bit KVM L0. Fixes: f9eb4af6 ("KVM: nVMX: VMX instructions: add checks for #GP/#SS exceptions") Cc: stable@vger.kernel.org Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Sean Christopherson 提交于
commit ddfd1730fd829743e41213e32ccc8b4aa6dc8325 upstream. When installing new memslots, KVM sets bit 0 of the generation number to indicate that an update is in-progress. Until the update is complete, there are no guarantees as to whether a vCPU will see the old or the new memslots. Explicity prevent caching MMIO accesses so as to avoid using an access cached from the old memslots after the new memslots have been installed. Note that it is unclear whether or not disabling caching during the update window is strictly necessary as there is no definitive documentation as to what ordering guarantees KVM provides with respect to updating memslots. That being said, the MMIO spte code does not allow reusing sptes created while an update is in-progress, and the associated documentation explicitly states: We do not want to use an MMIO sptes created with an odd generation number, ... If KVM is unlucky and creates an MMIO spte while the low bit is 1, the next access to the spte will always be a cache miss. At the very least, disabling the per-vCPU MMIO cache during updates will make its behavior consistent with the MMIO spte behavior and documentation. Fixes: 56f17dd3 ("kvm: x86: fix stale mmio cache bug") Cc: <stable@vger.kernel.org> Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Sean Christopherson 提交于
commit e1359e2beb8b0a1188abc997273acbaedc8ee791 upstream. The check to detect a wrap of the MMIO generation explicitly looks for a generation number of zero. Now that unique memslots generation numbers are assigned to each address space, only address space 0 will get a generation number of exactly zero when wrapping. E.g. when address space 1 goes from 0x7fffe to 0x80002, the MMIO generation number will wrap to 0x2. Adjust the MMIO generation to strip the address space modifier prior to checking for a wrap. Fixes: 4bd518f1 ("KVM: use separate generations for each address space") Cc: <stable@vger.kernel.org> Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Sean Christopherson 提交于
commit 152482580a1b0accb60676063a1ac57b2d12daf6 upstream. kvm_arch_memslots_updated() is at this point in time an x86-specific hook for handling MMIO generation wraparound. x86 stashes 19 bits of the memslots generation number in its MMIO sptes in order to avoid full page fault walks for repeat faults on emulated MMIO addresses. Because only 19 bits are used, wrapping the MMIO generation number is possible, if unlikely. kvm_arch_memslots_updated() alerts x86 that the generation has changed so that it can invalidate all MMIO sptes in case the effective MMIO generation has wrapped so as to avoid using a stale spte, e.g. a (very) old spte that was created with generation==0. Given that the purpose of kvm_arch_memslots_updated() is to prevent consuming stale entries, it needs to be called before the new generation is propagated to memslots. Invalidating the MMIO sptes after updating memslots means that there is a window where a vCPU could dereference the new memslots generation, e.g. 0, and incorrectly reuse an old MMIO spte that was created with (pre-wrap) generation==0. Fixes: e59dbe09 ("KVM: Introduce kvm_arch_memslots_updated()") Cc: <stable@vger.kernel.org> Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 06 3月, 2019 2 次提交
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由 Vitaly Kuznetsov 提交于
[ Upstream commit 619ad846fc3452adaf71ca246c5aa711e2055398 ] kvm-unit-tests' eventinj "NMI failing on IDT" test results in NMI being delivered to the host (L1) when it's running nested. The problem seems to be: svm_complete_interrupts() raises 'nmi_injected' flag but later we decide to reflect EXIT_NPF to L1. The flag remains pending and we do NMI injection upon entry so it got delivered to L1 instead of L2. It seems that VMX code solves the same issue in prepare_vmcs12(), this was introduced with code refactoring in commit 5f3d5799 ("KVM: nVMX: Rework event injection and recovery"). Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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由 Suravee Suthikulpanit 提交于
[ Upstream commit bb218fbcfaaa3b115d4cd7a43c0ca164f3a96e57 ] In case of incomplete IPI with invalid interrupt type, the current SVM driver does not properly emulate the IPI, and fails to boot FreeBSD guests with multiple vcpus when enabling AVIC. Fix this by update APIC ICR high/low registers, which also emulate sending the IPI. Signed-off-by: NSuravee Suthikulpanit <suravee.suthikulpanit@amd.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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- 27 2月, 2019 1 次提交
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由 Yu Zhang 提交于
commit 511da98d207d5c0675a10351b01e37cbe50a79e5 upstream. Previously, 'commit 372fddf7 ("x86/mm: Introduce the 'no5lvl' kernel parameter")' cleared X86_FEATURE_LA57 in boot_cpu_data, if Linux chooses to not run in 5-level paging mode. Yet boot_cpu_data is queried by do_cpuid_ent() as the host capability later when creating vcpus, and Qemu will not be able to detect this feature and create VMs with LA57 feature. As discussed earlier, VMs can still benefit from extended linear address width, e.g. to enhance features like ASLR. So we would like to fix this, by return the true hardware capability when Qemu queries. Signed-off-by: NYu Zhang <yu.c.zhang@linux.intel.com> Cc: stable@vger.kernel.org Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 20 2月, 2019 3 次提交
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由 Xiaoyao Li 提交于
commit 98ae70cc476e833332a2c6bb72f941a25f0de226 upstream. Commit ca83b4a7 ("x86/KVM/VMX: Add find_msr() helper function") introduces the helper function find_msr(), which returns -ENOENT when not find the msr in vmx->msr_autoload.guest/host. Correct checking contion of no more available entry in vmx->msr_autoload. Fixes: ca83b4a7 ("x86/KVM/VMX: Add find_msr() helper function") Cc: stable@vger.kernel.org Signed-off-by: NXiaoyao Li <xiaoyao.li@linux.intel.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Vitaly Kuznetsov 提交于
commit 6b1971c694975e49af302229202c0043568b1791 upstream. SDM says MSR_IA32_VMX_PROCBASED_CTLS2 is only available "If (CPUID.01H:ECX.[5] && IA32_VMX_PROCBASED_CTLS[63])". It was found that some old cpus (namely "Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz (family: 0x6, model: 0xf, stepping: 0x6") don't have it. Add the missing check. Reported-by: NZdenek Kaspar <zkaspar82@gmail.com> Tested-by: NZdenek Kaspar <zkaspar82@gmail.com> Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: NJim Mattson <jmattson@google.com> Cc: stable@vger.kernel.org Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 David Rientjes 提交于
[ Upstream commit 3f14a89d1132dcae3c8ce6721c6ef51f6e6d9b5f ] By code inspection, it was found that multiple calls to KVM_SEV_INIT could deplete asid bits and overwrite kvm_sev_info's regions_list. Multiple calls to KVM_SVM_INIT is not likely to occur with QEMU, but this should likely be fixed anyway. This code is serialized by kvm->lock. Fixes: 1654efcb ("KVM: SVM: Add KVM_SEV_INIT command") Reported-by: NCfir Cohen <cfir@google.com> Signed-off-by: NDavid Rientjes <rientjes@google.com> Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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- 13 2月, 2019 4 次提交
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由 Josh Poimboeuf 提交于
commit b284909abad48b07d3071a9fc9b5692b3e64914b upstream. With the following commit: 73d5e2b4 ("cpu/hotplug: detect SMT disabled by BIOS") ... the hotplug code attempted to detect when SMT was disabled by BIOS, in which case it reported SMT as permanently disabled. However, that code broke a virt hotplug scenario, where the guest is booted with only primary CPU threads, and a sibling is brought online later. The problem is that there doesn't seem to be a way to reliably distinguish between the HW "SMT disabled by BIOS" case and the virt "sibling not yet brought online" case. So the above-mentioned commit was a bit misguided, as it permanently disabled SMT for both cases, preventing future virt sibling hotplugs. Going back and reviewing the original problems which were attempted to be solved by that commit, when SMT was disabled in BIOS: 1) /sys/devices/system/cpu/smt/control showed "on" instead of "notsupported"; and 2) vmx_vm_init() was incorrectly showing the L1TF_MSG_SMT warning. I'd propose that we instead consider #1 above to not actually be a problem. Because, at least in the virt case, it's possible that SMT wasn't disabled by BIOS and a sibling thread could be brought online later. So it makes sense to just always default the smt control to "on" to allow for that possibility (assuming cpuid indicates that the CPU supports SMT). The real problem is #2, which has a simple fix: change vmx_vm_init() to query the actual current SMT state -- i.e., whether any siblings are currently online -- instead of looking at the SMT "control" sysfs value. So fix it by: a) reverting the original "fix" and its followup fix: 73d5e2b4 ("cpu/hotplug: detect SMT disabled by BIOS") bc2d8d26 ("cpu/hotplug: Fix SMT supported evaluation") and b) changing vmx_vm_init() to query the actual current SMT state -- instead of the sysfs control value -- to determine whether the L1TF warning is needed. This also requires the 'sched_smt_present' variable to exported, instead of 'cpu_smt_control'. Fixes: 73d5e2b4 ("cpu/hotplug: detect SMT disabled by BIOS") Reported-by: NIgor Mammedov <imammedo@redhat.com> Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Joe Mario <jmario@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: kvm@vger.kernel.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/e3a85d585da28cc333ecbc1e78ee9216e6da9396.1548794349.git.jpoimboe@redhat.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Peter Shier 提交于
commit ecec76885bcfe3294685dc363fd1273df0d5d65f upstream. Bugzilla: 1671904 There are multiple code paths where an hrtimer may have been started to emulate an L1 VMX preemption timer that can result in a call to free_nested without an intervening L2 exit where the hrtimer is normally cancelled. Unconditionally cancel in free_nested to cover all cases. Embargoed until Feb 7th 2019. Signed-off-by: NPeter Shier <pshier@google.com> Reported-by: NJim Mattson <jmattson@google.com> Reviewed-by: NJim Mattson <jmattson@google.com> Reported-by: NFelix Wilhelm <fwilhelm@google.com> Cc: stable@kernel.org Message-Id: <20181011184646.154065-1-pshier@google.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Paolo Bonzini 提交于
commit 353c0956a618a07ba4bbe7ad00ff29fe70e8412a upstream. Bugzilla: 1671930 Emulation of certain instructions (VMXON, VMCLEAR, VMPTRLD, VMWRITE with memory operand, INVEPT, INVVPID) can incorrectly inject a page fault when passed an operand that points to an MMIO address. The page fault will use uninitialized kernel stack memory as the CR2 and error code. The right behavior would be to abort the VM with a KVM_EXIT_INTERNAL_ERROR exit to userspace; however, it is not an easy fix, so for now just ensure that the error code and CR2 are zero. Embargoed until Feb 7th 2019. Reported-by: NFelix Wilhelm <fwilhelm@google.com> Cc: stable@kernel.org Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Vitaly Kuznetsov 提交于
[ Upstream commit e87555e550cef4941579cd879759a7c0dee24e68 ] AMD doesn't seem to implement MSR_IA32_MCG_EXT_CTL and svm code in kvm knows nothing about it, however, this MSR is among emulated_msrs and thus returned with KVM_GET_MSR_INDEX_LIST. The consequent KVM_GET_MSRS, of course, fails. Report the MSR as unsupported to not confuse userspace. Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com> Signed-off-by: NSasha Levin <sashal@kernel.org>
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- 31 1月, 2019 2 次提交
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由 KarimAllah Ahmed 提交于
commit 22a7cdcae6a4a3c8974899e62851d270956f58ce upstream. The spec only requires the posted interrupt descriptor address to be 64-bytes aligned (i.e. bits[0:5] == 0). Using page_address_valid also forces the address to be page aligned. Only validate that the address does not cross the maximum physical address without enforcing a page alignment. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Fixes: 6de84e58 ("nVMX x86: check posted-interrupt descriptor addresss on vmentry of L2") Signed-off-by: NKarimAllah Ahmed <karahmed@amazon.de> Reviewed-by: NJim Mattson <jmattson@google.com> Reviewed-by: NKrish Sadhuhan <krish.sadhukhan@oracle.com> Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com> From: Mark Mielke <mark.mielke@gmail.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Tom Roeder 提交于
commit 3a33d030daaa7c507e1c12d5adcf828248429593 upstream. This changes the allocation of cached_vmcs12 to use kzalloc instead of kmalloc. This removes the information leak found by Syzkaller (see Reported-by) in this case and prevents similar leaks from happening based on cached_vmcs12. It also changes vmx_get_nested_state to copy out the full 4k VMCS12_SIZE in copy_to_user rather than only the size of the struct. Tested: rebuilt against head, booted, and ran the syszkaller repro https://syzkaller.appspot.com/text?tag=ReproC&x=174efca3400000 without observing any problems. Reported-by: syzbot+ded1696f6b50b615b630@syzkaller.appspotmail.com Fixes: 8fcc4b59 Cc: stable@vger.kernel.org Signed-off-by: NTom Roeder <tmroeder@google.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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