The functions kvmppc_st and kvmppc_ld are used to access guest memory
from the host using a guest effective address. They do so by translating
through the process table to obtain a guest real address and then using
kvm_read_guest or kvm_write_guest to make the access with the guest real
address.

This method of access however only works for L1 guests and will give the
incorrect results for a nested guest.

We can however use the store_to_eaddr and load_from_eaddr kvmppc_ops to
perform the access for a nested guesti (and a L1 guest). So attempt this
method first and fall back to the old method if this fails and we aren't
running a nested guest.

At this stage there is no fall back method to perform the access for a
nested guest and this is left as a future improvement. For now we will
return to the nested guest and rely on the fact that a translation
should be faulted in before retrying the access.
Signed-off-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

The kvmppc_ops struct is used to store function pointers to kvm
implementation specific functions.

Introduce two new functions load_from_eaddr and store_to_eaddr to be
used to load from and store to a guest effective address respectively.

Also implement these for the kvm-hv module. If we are using the radix
mmu then we can call the functions to access quadrant 1 and 2.
Signed-off-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

The POWER9 radix mmu has the concept of quadrants. The quadrant number
is the two high bits of the effective address and determines the fully
qualified address to be used for the translation. The fully qualified
address consists of the effective lpid, the effective pid and the
effective address. This gives then 4 possible quadrants 0, 1, 2, and 3.

When accessing these quadrants the fully qualified address is obtained
as follows:

Quadrant		| Hypervisor		| Guest
--------------------------------------------------------------------------
			| EA[0:1] = 0b00	| EA[0:1] = 0b00
0			| effLPID = 0		| effLPID = LPIDR
			| effPID  = PIDR	| effPID  = PIDR
--------------------------------------------------------------------------
			| EA[0:1] = 0b01	|
1			| effLPID = LPIDR	| Invalid Access
			| effPID  = PIDR	|
--------------------------------------------------------------------------
			| EA[0:1] = 0b10	|
2			| effLPID = LPIDR	| Invalid Access
			| effPID  = 0		|
--------------------------------------------------------------------------
			| EA[0:1] = 0b11	| EA[0:1] = 0b11
3			| effLPID = 0		| effLPID = LPIDR
			| effPID  = 0		| effPID  = 0
--------------------------------------------------------------------------

In the Guest;
Quadrant 3 is normally used to address the operating system since this
uses effPID=0 and effLPID=LPIDR, meaning the PID register doesn't need to
be switched.
Quadrant 0 is normally used to address user space since the effLPID and
effPID are taken from the corresponding registers.

In the Host;
Quadrant 0 and 3 are used as above, however the effLPID is always 0 to
address the host.

Quadrants 1 and 2 can be used by the host to address guest memory using
a guest effective address. Since the effLPID comes from the LPID register,
the host loads the LPID of the guest it would like to access (and the
PID of the process) and can perform accesses to a guest effective
address.

This means quadrant 1 can be used to address the guest user space and
quadrant 2 can be used to address the guest operating system from the
hypervisor, using a guest effective address.

Access to the quadrants can cause a Hypervisor Data Storage Interrupt
(HDSI) due to being unable to perform partition scoped translation.
Previously this could only be generated from a guest and so the code
path expects us to take the KVM trampoline in the interrupt handler.
This is no longer the case so we modify the handler to call
bad_page_fault() to check if we were expecting this fault so we can
handle it gracefully and just return with an error code. In the hash mmu
case we still raise an unknown exception since quadrants aren't defined
for the hash mmu.
Signed-off-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

There exists a function kvm_is_radix() which is used to determine if a
kvm instance is using the radix mmu. However this only applies to the
first level (L1) guest. Add a function kvmhv_vcpu_is_radix() which can
be used to determine if the current execution context of the vcpu is
radix, accounting for if the vcpu is running a nested guest.

Currently all nested guests must be radix but this may change in the
future.
Signed-off-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

The kvm capability KVM_CAP_SPAPR_TCE_VFIO is used to indicate the
availability of in kernel tce acceleration for vfio. However it is
currently the case that this is only available on a powernv machine,
not for a pseries machine.

Thus make this capability dependent on having the cpu feature
CPU_FTR_HVMODE.

[paulus@ozlabs.org - fixed compilation for Book E.]
Signed-off-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

This adds code to flush the partition-scoped page tables for a radix
guest when dirty tracking is turned on or off for a memslot.  Only the
guest real addresses covered by the memslot are flushed.  The reason
for this is to get rid of any 2M PTEs in the partition-scoped page
tables that correspond to host transparent huge pages, so that page
dirtiness is tracked at a system page (4k or 64k) granularity rather
than a 2M granularity.  The page tables are also flushed when turning
dirty tracking off so that the memslot's address space can be
repopulated with THPs if possible.

To do this, we add a new function kvmppc_radix_flush_memslot().  Since
this does what's needed for kvmppc_core_flush_memslot_hv() on a radix
guest, we now make kvmppc_core_flush_memslot_hv() call the new
kvmppc_radix_flush_memslot() rather than calling kvm_unmap_radix()
for each page in the memslot.  This has the effect of fixing a bug in
that kvmppc_core_flush_memslot_hv() was previously calling
kvm_unmap_radix() without holding the kvm->mmu_lock spinlock, which
is required to be held.
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>
Reviewed-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

This adds 'const' to the declarations for the struct kvm_memory_slot
pointer parameters of some functions, which will make it possible to
call those functions from kvmppc_core_commit_memory_region_hv()
in the next patch.

This also fixes some comments about locking.
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>
Reviewed-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

For radix guests, this makes KVM map guest memory as individual pages
when dirty page logging is enabled for the memslot corresponding to the
guest real address.  Having a separate partition-scoped PTE for each
system page mapped to the guest means that we have a separate dirty
bit for each page, thus making the reported dirty bitmap more accurate.
Without this, if part of guest memory is backed by transparent huge
pages, the dirty status is reported at a 2MB granularity rather than
a 64kB (or 4kB) granularity for that part, causing userspace to have
to transmit more data when migrating the guest.
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>
Reviewed-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

Currently, kvm_arch_commit_memory_region() gets called with a
parameter indicating what type of change is being made to the memslot,
but it doesn't pass it down to the platform-specific memslot commit
functions.  This adds the `change' parameter to the lower-level
functions so that they can use it in future.

[paulus@ozlabs.org - fix book E also.]
Signed-off-by: NBharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

When booting a kvm-pr guest on a POWER9 machine the following message is
observed:
"qemu-system-ppc64: KVM does not support 1TiB segments which guest expects"

This is because the guest is expecting to be able to use 1T segments
however we don't indicate support for it. This is because we don't set
the BOOK3S_HFLAG_MULTI_PGSIZE flag in the hflags in kvmppc_set_pvr_pr()
on POWER9.

POWER9 does indeed have support for 1T segments, so add a case for
POWER9 to the switch statement to ensure it is set.
Signed-off-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.
Signed-off-by: NYangtao Li <tiny.windzz@gmail.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

Testing has revealed an occasional crash which appears to be caused
by a race between kvmppc_switch_mmu_to_hpt and kvm_unmap_hva_range_hv.
The symptom is a NULL pointer dereference in __find_linux_pte() called
from kvm_unmap_radix() with kvm->arch.pgtable == NULL.

Looking at kvmppc_switch_mmu_to_hpt(), it does indeed clear
kvm->arch.pgtable (via kvmppc_free_radix()) before setting
kvm->arch.radix to NULL, and there is nothing to prevent
kvm_unmap_hva_range_hv() or the other MMU callback functions from
being called concurrently with kvmppc_switch_mmu_to_hpt() or
kvmppc_switch_mmu_to_radix().

This patch therefore adds calls to spin_lock/unlock on the kvm->mmu_lock
around the assignments to kvm->arch.radix, and makes sure that the
partition-scoped radix tree or HPT is only freed after changing
kvm->arch.radix.

This also takes the kvm->mmu_lock in kvmppc_rmap_reset() to make sure
that the clearing of each rmap array (one per memslot) doesn't happen
concurrently with use of the array in the kvm_unmap_hva_range_hv()
or the other MMU callbacks.

Fixes: 18c3640c ("KVM: PPC: Book3S HV: Add infrastructure for running HPT guests on radix host")
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

Previously, we only called indirect_branch_prediction_barrier on the
logical CPU that freed a vmcb. This function should be called on all
logical CPUs that last loaded the vmcb in question.

Fixes: 15d45071 ("KVM/x86: Add IBPB support")
Reported-by: NNeel Natu <neelnatu@google.com>
Signed-off-by: NJim Mattson <jmattson@google.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

When a guest page table is updated via an emulated write,
kvm_mmu_pte_write() is called to update the shadow PTE using the just
written guest PTE value. But if two emulated guest PTE writes happened
concurrently, it is possible that the guest PTE and the shadow PTE end
up being out of sync. Emulated writes do not mark the shadow page as
unsync-ed, so this inconsistency will not be resolved even by a guest TLB
flush (unless the page was marked as unsync-ed at some other point).

This is fixed by re-reading the current value of the guest PTE after the
MMU lock has been acquired instead of just using the value that was
written prior to calling kvm_mmu_pte_write().
Signed-off-by: NJunaid Shahid <junaids@google.com>
Reviewed-by: NWanpeng Li <wanpengli@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

vmcs12 represents the per-CPU cache of L1 active vmcs12.

This cache can be loaded by one of the following:
1) Guest making a vmcs12 active by exeucting VMPTRLD
2) Guest specifying eVMCS in VP assist page and executing
VMLAUNCH/VMRESUME.

Either way, vmcs12 should have revision_id of VMCS12_REVISION.
Which is not equal to eVMCS revision_id which specifies used
VersionNumber of eVMCS struct (e.g. KVM_EVMCS_VERSION).

Specifically, this causes an issue in restoring a nested VM state
because vmx_set_nested_state() verifies that vmcs12->revision_id
is equal to VMCS12_REVISION which was not true in case vmcs12
was populated from an eVMCS by vmx_get_nested_state() which calls
copy_enlightened_to_vmcs12().
Reviewed-by: NDarren Kenny <darren.kenny@oracle.com>
Signed-off-by: NLiran Alon <liran.alon@oracle.com>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

According to TLFS section 16.11.2 Enlightened VMCS, the first u32
field of eVMCS should specify eVMCS VersionNumber.

This version should be in the range of supported eVMCS versions exposed
to guest via CPUID.0x4000000A.EAX[0:15].
The range which KVM expose to guest in this CPUID field should be the
same as the value returned in vmcs_version by nested_enable_evmcs().

According to the above, eVMCS VMPTRLD should verify that version specified
in given eVMCS is in the supported range. However, current code
mistakenly verfies this field against VMCS12_REVISION.

One can also see that when KVM use eVMCS, it makes sure that
alloc_vmcs_cpu() sets allocated eVMCS revision_id to KVM_EVMCS_VERSION.

Obvious fix should just change eVMCS VMPTRLD to verify first u32 field
of eVMCS is equal to KVM_EVMCS_VERSION.
However, it turns out that Microsoft Hyper-V fails to comply to their
own invented interface: When Hyper-V use eVMCS, it just sets first u32
field of eVMCS to revision_id specified in MSR_IA32_VMX_BASIC (In our
case: VMCS12_REVISION). Instead of used eVMCS version number which is
one of the supported versions specified in CPUID.0x4000000A.EAX[0:15].
To overcome Hyper-V bug, we accept either a supported eVMCS version
or VMCS12_REVISION as valid values for first u32 field of eVMCS.

Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: NNikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: NMark Kanda <mark.kanda@oracle.com>
Signed-off-by: NLiran Alon <liran.alon@oracle.com>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Since commit e79f245d ("X86/KVM: Properly update 'tsc_offset' to
represent the running guest"), vcpu->arch.tsc_offset meaning was
changed to always reflect the tsc_offset value set on active VMCS.
Regardless if vCPU is currently running L1 or L2.

However, above mentioned commit failed to also change
kvm_vcpu_write_tsc_offset() to set vcpu->arch.tsc_offset correctly.
This is because vmx_write_tsc_offset() could set the tsc_offset value
in active VMCS to given offset parameter *plus vmcs12->tsc_offset*.
However, kvm_vcpu_write_tsc_offset() just sets vcpu->arch.tsc_offset
to given offset parameter. Without taking into account the possible
addition of vmcs12->tsc_offset. (Same is true for SVM case).

Fix this issue by changing kvm_x86_ops->write_tsc_offset() to return
actually set tsc_offset in active VMCS and modify
kvm_vcpu_write_tsc_offset() to set returned value in
vcpu->arch.tsc_offset.
In addition, rename write_tsc_offset() callback to write_l1_tsc_offset()
to make it clear that it is meant to set L1 TSC offset.

Fixes: e79f245d ("X86/KVM: Properly update 'tsc_offset' to represent the running guest")
Reviewed-by: NLiran Alon <liran.alon@oracle.com>
Reviewed-by: NMihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: NLeonid Shatz <leonid.shatz@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The inline keyword which is not at the beginning of the function
declaration may trigger the following build warnings, so let's fix it:

arch/x86/kvm/vmx.c:1309:1: warning: ‘inline’ is not at beginning of declaration [-Wold-style-declaration]
arch/x86/kvm/vmx.c:5947:1: warning: ‘inline’ is not at beginning of declaration [-Wold-style-declaration]
arch/x86/kvm/vmx.c:5985:1: warning: ‘inline’ is not at beginning of declaration [-Wold-style-declaration]
arch/x86/kvm/vmx.c:6023:1: warning: ‘inline’ is not at beginning of declaration [-Wold-style-declaration]
Signed-off-by: NYi Wang <wang.yi59@zte.com.cn>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

We get the following warnings about empty statements when building
with 'W=1':

arch/x86/kvm/lapic.c:632:53: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
arch/x86/kvm/lapic.c:1907:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
arch/x86/kvm/lapic.c:1936:65: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
arch/x86/kvm/lapic.c:1975:44: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]

Rework the debug helper macro to get rid of these warnings.
Signed-off-by: NYi Wang <wang.yi59@zte.com.cn>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

When guest transitions from/to long-mode by modifying MSR_EFER.LMA,
the list of shared MSRs to be saved/restored on guest<->host
transitions is updated (See vmx_set_efer() call to setup_msrs()).

On every entry to guest, vcpu_enter_guest() calls
vmx_prepare_switch_to_guest(). This function should also take care
of setting the shared MSRs to be saved/restored. However, the
function does nothing in case we are already running with loaded
guest state (vmx->loaded_cpu_state != NULL).

This means that even when guest modifies MSR_EFER.LMA which results
in updating the list of shared MSRs, it isn't being taken into account
by vmx_prepare_switch_to_guest() because it happens while we are
running with loaded guest state.

To fix above mentioned issue, add a flag to mark that the list of
shared MSRs has been updated and modify vmx_prepare_switch_to_guest()
to set shared MSRs when running with host state *OR* list of shared
MSRs has been updated.

Note that this issue was mistakenly introduced by commit
678e315e ("KVM: vmx: add dedicated utility to access guest's
kernel_gs_base") because previously vmx_set_efer() always called
vmx_load_host_state() which resulted in vmx_prepare_switch_to_guest() to
set shared MSRs.

Fixes: 678e315e ("KVM: vmx: add dedicated utility to access guest's kernel_gs_base")
Reported-by: NEyal Moscovici <eyal.moscovici@oracle.com>
Reviewed-by: NMihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: NLiam Merwick <liam.merwick@oracle.com>
Reviewed-by: NJim Mattson <jmattson@google.com>
Signed-off-by: NLiran Alon <liran.alon@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

kvm_pv_clock_pairing() allocates local var
"struct kvm_clock_pairing clock_pairing" on stack and initializes
all it's fields besides padding (clock_pairing.pad[]).

Because clock_pairing var is written completely (including padding)
to guest memory, failure to init struct padding results in kernel
info-leak.

Fix the issue by making sure to also init the padding with zeroes.

Fixes: 55dd00a7 ("KVM: x86: add KVM_HC_CLOCK_PAIRING hypercall")
Reported-by: syzbot+a8ef68d71211ba264f56@syzkaller.appspotmail.com
Reviewed-by: NMark Kanda <mark.kanda@oracle.com>
Signed-off-by: NLiran Alon <liran.alon@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Consider the case that userspace enables KVM_CAP_HYPERV_ENLIGHTENED_VMCS twice:
1) kvm_vcpu_ioctl_enable_cap() is called to enable
KVM_CAP_HYPERV_ENLIGHTENED_VMCS which calls nested_enable_evmcs().
2) nested_enable_evmcs() sets enlightened_vmcs_enabled to true and fills
vmcs_version which is then copied to userspace.
3) kvm_vcpu_ioctl_enable_cap() is called again to enable
KVM_CAP_HYPERV_ENLIGHTENED_VMCS which calls nested_enable_evmcs().
4) This time nested_enable_evmcs() just returns 0 as
enlightened_vmcs_enabled is already true. *Without filling
vmcs_version*.
5) kvm_vcpu_ioctl_enable_cap() continues as usual and copies
*uninitialized* vmcs_version to userspace which leads to kernel info-leak.

Fix this issue by simply changing nested_enable_evmcs() to always fill
vmcs_version output argument. Even when enlightened_vmcs_enabled is
already set to true.

Note that SVM's nested_enable_evmcs() should not be modified because it
always returns a non-zero value (-ENODEV) which results in
kvm_vcpu_ioctl_enable_cap() skipping the copy of vmcs_version to
userspace (as it should).

Fixes: 57b119da ("KVM: nVMX: add KVM_CAP_HYPERV_ENLIGHTENED_VMCS capability")
Reported-by: syzbot+cfbc368e283d381f8cef@syzkaller.appspotmail.com
Reviewed-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NLiran Alon <liran.alon@oracle.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

There is a race condition when accessing kvm->arch.apic_access_page_done.
Due to it, x86_set_memory_region will fail when creating the second vcpu
for a svm guest.

Add a mutex_lock to serialize the accesses to apic_access_page_done.
This lock is also used by vmx for the same purpose.
Signed-off-by: NWei Wang <wawei@amazon.de>
Signed-off-by: NAmadeusz Juskowiak <ajusk@amazon.de>
Signed-off-by: NJulian Stecklina <jsteckli@amazon.de>
Signed-off-by: NSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: NJoerg Roedel <jroedel@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Reported by syzkaller:

 BUG: unable to handle kernel NULL pointer dereference at 00000000000001c8
 PGD 80000003ec4da067 P4D 80000003ec4da067 PUD 3f7bfa067 PMD 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 7 PID: 5059 Comm: debug Tainted: G           OE     4.19.0-rc5 #16
 RIP: 0010:__lock_acquire+0x1a6/0x1990
 Call Trace:
  lock_acquire+0xdb/0x210
  _raw_spin_lock+0x38/0x70
  kvm_ioapic_scan_entry+0x3e/0x110 [kvm]
  vcpu_enter_guest+0x167e/0x1910 [kvm]
  kvm_arch_vcpu_ioctl_run+0x35c/0x610 [kvm]
  kvm_vcpu_ioctl+0x3e9/0x6d0 [kvm]
  do_vfs_ioctl+0xa5/0x690
  ksys_ioctl+0x6d/0x80
  __x64_sys_ioctl+0x1a/0x20
  do_syscall_64+0x83/0x6e0
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

The reason is that the testcase writes hyperv synic HV_X64_MSR_SINT6 msr
and triggers scan ioapic logic to load synic vectors into EOI exit bitmap.
However, irqchip is not initialized by this simple testcase, ioapic/apic
objects should not be accessed.
This can be triggered by the following program:

    #define _GNU_SOURCE

    #include <endian.h>
    #include <stdint.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <sys/syscall.h>
    #include <sys/types.h>
    #include <unistd.h>

    uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff};

    int main(void)
    {
    	syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
    	long res = 0;
    	memcpy((void*)0x20000040, "/dev/kvm", 9);
    	res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000040, 0, 0);
    	if (res != -1)
    		r[0] = res;
    	res = syscall(__NR_ioctl, r[0], 0xae01, 0);
    	if (res != -1)
    		r[1] = res;
    	res = syscall(__NR_ioctl, r[1], 0xae41, 0);
    	if (res != -1)
    		r[2] = res;
    	memcpy(
    			(void*)0x20000080,
    			"\x01\x00\x00\x00\x00\x5b\x61\xbb\x96\x00\x00\x40\x00\x00\x00\x00\x01\x00"
    			"\x08\x00\x00\x00\x00\x00\x0b\x77\xd1\x78\x4d\xd8\x3a\xed\xb1\x5c\x2e\x43"
    			"\xaa\x43\x39\xd6\xff\xf5\xf0\xa8\x98\xf2\x3e\x37\x29\x89\xde\x88\xc6\x33"
    			"\xfc\x2a\xdb\xb7\xe1\x4c\xac\x28\x61\x7b\x9c\xa9\xbc\x0d\xa0\x63\xfe\xfe"
    			"\xe8\x75\xde\xdd\x19\x38\xdc\x34\xf5\xec\x05\xfd\xeb\x5d\xed\x2e\xaf\x22"
    			"\xfa\xab\xb7\xe4\x42\x67\xd0\xaf\x06\x1c\x6a\x35\x67\x10\x55\xcb",
    			106);
    	syscall(__NR_ioctl, r[2], 0x4008ae89, 0x20000080);
    	syscall(__NR_ioctl, r[2], 0xae80, 0);
    	return 0;
    }

This patch fixes it by bailing out scan ioapic if ioapic is not initialized in
kernel.
Reported-by: NWei Wu <ww9210@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Wei Wu <ww9210@gmail.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Reported by syzkaller:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000014
 PGD 800000040410c067 P4D 800000040410c067 PUD 40410d067 PMD 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 3 PID: 2567 Comm: poc Tainted: G           OE     4.19.0-rc5 #16
 RIP: 0010:kvm_pv_send_ipi+0x94/0x350 [kvm]
 Call Trace:
  kvm_emulate_hypercall+0x3cc/0x700 [kvm]
  handle_vmcall+0xe/0x10 [kvm_intel]
  vmx_handle_exit+0xc1/0x11b0 [kvm_intel]
  vcpu_enter_guest+0x9fb/0x1910 [kvm]
  kvm_arch_vcpu_ioctl_run+0x35c/0x610 [kvm]
  kvm_vcpu_ioctl+0x3e9/0x6d0 [kvm]
  do_vfs_ioctl+0xa5/0x690
  ksys_ioctl+0x6d/0x80
  __x64_sys_ioctl+0x1a/0x20
  do_syscall_64+0x83/0x6e0
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

The reason is that the apic map has not yet been initialized, the testcase
triggers pv_send_ipi interface by vmcall which results in kvm->arch.apic_map
is dereferenced. This patch fixes it by checking whether or not apic map is
NULL and bailing out immediately if that is the case.

Fixes: 4180bf1b (KVM: X86: Implement "send IPI" hypercall)
Reported-by: NWei Wu <ww9210@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Wei Wu <ww9210@gmail.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Apparently, the ple_gap parameter was accidentally removed
by commit c8e88717. Add it
back.
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
Cc: stable@vger.kernel.org
Fixes: c8e88717Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The new memory EFI reservation feature we introduced to allow memory
reservations to persist across kexec may trigger an unbounded number
of calls to memblock_reserve(). The memblock subsystem can deal with
this fine, but not before memblock resizing is enabled, which we can
only do after paging_init(), when the memory we reallocate the array
into is actually mapped.

So break out the memreserve table processing into a separate routine
and call it after paging_init() on arm64. On ARM, because of limited
reviewing bandwidth of the maintainer, we cannot currently fix this,
so instead, disable the EFI persistent memreserve entirely on ARM so
we can fix it later.
Tested-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181114175544.12860-5-ard.biesheuvel@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Commit 4c2de74c ("powerpc/64: Interrupts save PPR on stack rather
than thread_struct") changed sizeof(struct pt_regs) % 16 from 0 to 8,
which causes the interrupt frame allocation on kernel entry to put the
kernel stack out of alignment.

Quadword (16-byte) alignment for the stack is required by both the
64-bit v1 ABI (v1.9 § 3.2.2) and the 64-bit v2 ABI (v1.1 § 2.2.2.1).

Add a pad field to fix alignment, and add a BUILD_BUG_ON to catch this
in future.

Fixes: 4c2de74c ("powerpc/64: Interrupts save PPR on stack rather than thread_struct")
Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

While running a nested guest VCPU on L0 via H_ENTER_NESTED hcall, a
pending signal in the L0 QEMU process can generate the following
sequence:

  ret0 = kvmppc_pseries_do_hcall()
    ret1 = kvmhv_enter_nested_guest()
      ret2 = kvmhv_run_single_vcpu()
      if (ret2 == -EINTR)
        return H_INTERRUPT
    if (ret1 == H_INTERRUPT)
      kvmppc_set_gpr(vcpu, 3, 0)
      return -EINTR
    /* skipped: */
    kvmppc_set_gpr(vcpu, 3, ret)
    vcpu->arch.hcall_needed = 0
    return RESUME_GUEST

which causes an exit to L0 userspace with ret0 == -EINTR.

The intention seems to be to set the hcall return value to 0 (via
VCPU r3) so that L1 will see a successful return from H_ENTER_NESTED
once we resume executing the VCPU. However, because we don't set
vcpu->arch.hcall_needed = 0, we do the following once userspace
resumes execution via kvm_arch_vcpu_ioctl_run():

  ...
  } else if (vcpu->arch.hcall_needed) {
    int i

    kvmppc_set_gpr(vcpu, 3, run->papr_hcall.ret);
    for (i = 0; i < 9; ++i)
           kvmppc_set_gpr(vcpu, 4 + i, run->papr_hcall.args[i]);
    vcpu->arch.hcall_needed = 0;

since vcpu->arch.hcall_needed == 1 indicates that userspace should
have handled the hcall and stored the return value in
run->papr_hcall.ret. Since that's not the case here, we can get an
unexpected value in VCPU r3, which can result in
kvmhv_p9_guest_entry() reporting an unexpected trap value when it
returns from H_ENTER_NESTED, causing the following register dump to
console via subsequent call to kvmppc_handle_exit_hv() in L1:

  [  350.612854] vcpu 00000000f9564cf8 (0):
  [  350.612915] pc  = c00000000013eb98  msr = 8000000000009033  trap = 1
  [  350.613020] r 0 = c0000000004b9044  r16 = 0000000000000000
  [  350.613075] r 1 = c00000007cffba30  r17 = 0000000000000000
  [  350.613120] r 2 = c00000000178c100  r18 = 00007fffc24f3b50
  [  350.613166] r 3 = c00000007ef52480  r19 = 00007fffc24fff58
  [  350.613212] r 4 = 0000000000000000  r20 = 00000a1e96ece9d0
  [  350.613253] r 5 = 70616d00746f6f72  r21 = 00000a1ea117c9b0
  [  350.613295] r 6 = 0000000000000020  r22 = 00000a1ea1184360
  [  350.613338] r 7 = c0000000783be440  r23 = 0000000000000003
  [  350.613380] r 8 = fffffffffffffffc  r24 = 00000a1e96e9e124
  [  350.613423] r 9 = c00000007ef52490  r25 = 00000000000007ff
  [  350.613469] r10 = 0000000000000004  r26 = c00000007eb2f7a0
  [  350.613513] r11 = b0616d0009eccdb2  r27 = c00000007cffbb10
  [  350.613556] r12 = c0000000004b9000  r28 = c00000007d83a2c0
  [  350.613597] r13 = c000000001b00000  r29 = c0000000783cdf68
  [  350.613639] r14 = 0000000000000000  r30 = 0000000000000000
  [  350.613681] r15 = 0000000000000000  r31 = c00000007cffbbf0
  [  350.613723] ctr = c0000000004b9000  lr  = c0000000004b9044
  [  350.613765] srr0 = 0000772f954dd48c srr1 = 800000000280f033
  [  350.613808] sprg0 = 0000000000000000 sprg1 = c000000001b00000
  [  350.613859] sprg2 = 0000772f9565a280 sprg3 = 0000000000000000
  [  350.613911] cr = 88002848  xer = 0000000020040000  dsisr = 42000000
  [  350.613962] dar = 0000772f95390000
  [  350.614031] fault dar = c000000244b278c0 dsisr = 00000000
  [  350.614073] SLB (0 entries):
  [  350.614157] lpcr = 0040000003d40413 sdr1 = 0000000000000000 last_inst = ffffffff
  [  350.614252] trap=0x1 | pc=0xc00000000013eb98 | msr=0x8000000000009033

followed by L1's QEMU reporting the following before stopping execution
of the nested guest:

  KVM: unknown exit, hardware reason 1
  NIP c00000000013eb98   LR c0000000004b9044 CTR c0000000004b9000 XER 0000000020040000 CPU#0
  MSR 8000000000009033 HID0 0000000000000000  HF 8000000000000000 iidx 3 didx 3
  TB 00000000 00000000 DECR 00000000
  GPR00 c0000000004b9044 c00000007cffba30 c00000000178c100 c00000007ef52480
  GPR04 0000000000000000 70616d00746f6f72 0000000000000020 c0000000783be440
  GPR08 fffffffffffffffc c00000007ef52490 0000000000000004 b0616d0009eccdb2
  GPR12 c0000000004b9000 c000000001b00000 0000000000000000 0000000000000000
  GPR16 0000000000000000 0000000000000000 00007fffc24f3b50 00007fffc24fff58
  GPR20 00000a1e96ece9d0 00000a1ea117c9b0 00000a1ea1184360 0000000000000003
  GPR24 00000a1e96e9e124 00000000000007ff c00000007eb2f7a0 c00000007cffbb10
  GPR28 c00000007d83a2c0 c0000000783cdf68 0000000000000000 c00000007cffbbf0
  CR 88002848  [ L  L  -  -  E  L  G  L  ]             RES ffffffffffffffff
   SRR0 0000772f954dd48c  SRR1 800000000280f033    PVR 00000000004e1202 VRSAVE 0000000000000000
  SPRG0 0000000000000000 SPRG1 c000000001b00000  SPRG2 0000772f9565a280  SPRG3 0000000000000000
  SPRG4 0000000000000000 SPRG5 0000000000000000  SPRG6 0000000000000000  SPRG7 0000000000000000
  HSRR0 0000000000000000 HSRR1 0000000000000000
   CFAR 0000000000000000
   LPCR 0000000003d40413
   PTCR 0000000000000000   DAR 0000772f95390000  DSISR 0000000042000000

Fix this by setting vcpu->arch.hcall_needed = 0 to indicate completion
of H_ENTER_NESTED before we exit to L0 userspace.

Fixes: 360cae31 ("KVM: PPC: Book3S HV: Nested guest entry via hypercall")
Cc: linuxppc-dev@ozlabs.org
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: NSuraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

The bootloader may pass physical address of the boot parameters structure
to the MMUv3 kernel in the register a2. Code in the _SetupMMU block in
the arch/xtensa/kernel/head.S is supposed to map that physical address to
the virtual address in the configured virtual memory layout.

This code haven't been updated when additional 256+256 and 512+512
memory layouts were introduced and it may produce wrong addresses when
used with these layouts.

Cc: stable@vger.kernel.org
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>

When VPHN function is not supported and during cpu hotplug event,
kernel prints message 'VPHN function not supported. Disabling
polling...'. Currently it prints on every hotplug event, it floods
dmesg when a KVM guest tries to hotplug huge number of vcpus, let's
just print once and suppress further kernel prints.
Signed-off-by: NSatheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Fixes:

arch/riscv/kernel/module.c: In function 'apply_r_riscv_32_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:23:27: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_pcrel_hi20_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:104:23: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_hi20_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:146:23: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_got_hi20_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:190:60: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_call_plt_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:214:24: note: format string is defined here
arch/riscv/kernel/module.c: In function 'apply_r_riscv_call_rela':
./include/linux/kern_levels.h:5:18: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'Elf32_Addr' {aka 'unsigned int'} [-Wformat=]
arch/riscv/kernel/module.c:236:23: note: format string is defined here
Signed-off-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Fixes the following build error from tinyconfig:

riscv64-unknown-linux-gnu-ld: kernel/sched/fair.o: in function `.L8':
fair.c:(.text+0x70): undefined reference to `__lshrti3'
riscv64-unknown-linux-gnu-ld: kernel/time/clocksource.o: in function `.L0 ':
clocksource.c:(.text+0x334): undefined reference to `__lshrti3'

Fixes: 7f47c73b ("RISC-V: Build tishift only on 64-bit")
Signed-off-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Building kernel 4.20 for Fedora as RPM fails, because riscv is missing
vdso_install target in arch/riscv/Makefile.
Signed-off-by: NDavid Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Replace 8 spaces with tab to match styling.
Signed-off-by: NDavid Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

The printk timestamps are very useful information to visually see
where kernel is spending time during boot. It also helps us see
the timing of hotplug events at runtime.

This patch enables printk timestamps in RISC-V defconfig so that
we have it enabled by default (similar to other architectures
such as x86_64, arm64, etc).
Signed-off-by: NAnup Patel <anup@brainfault.org>
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

In big.Little systems, some CPUs require the Spectre workarounds in
paths such as the context switch, but other CPUs do not.  In order
to handle these differences, we need per-CPU vtables.

We are unable to use the kernel's per-CPU variables to support this
as per-CPU is not initialised at times when we need access to the
vtables, so we have to use an array indexed by logical CPU number.

We use an array-of-pointers to avoid having function pointers in
the kernel's read/write .data section.
Reviewed-by: NJulien Thierry <julien.thierry@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

In vfp_preserve_user_clear_hwstate, ufp_exc->fpinst2 gets assigned to
itself. It should actually be hwstate->fpinst2 that gets assigned to the
ufp_exc field.

Fixes commit 3aa2df6e ("ARM: 8791/1:
vfp: use __copy_to_user() when saving VFP state").
Reported-by: NDavid Binderman <dcb314@hotmail.com>
Signed-off-by: NJulien Thierry <julien.thierry@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

Allow the way we access members of the processor vtable to be changed
at compile time.  We will need to move to per-CPU vtables to fix the
Spectre variant 2 issues on big.Little systems.

However, we have a couple of calls that do not need the vtable
treatment, and indeed cause a kernel warning due to the (later) use
of smp_processor_id(), so also introduce the PROC_TABLE macro for
these which always use CPU 0's function pointers.
Reviewed-by: NJulien Thierry <julien.thierry@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

Call the per-processor type check_bugs() method in the same way as we
do other per-processor functions - move the "processor." detail into
proc-fns.h.
Reviewed-by: NJulien Thierry <julien.thierry@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>