- 10 10月, 2014 1 次提交
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由 Ard Biesheuvel 提交于
Pass __GFP_ZERO to __get_free_pages() instead of calling memset() explicitly. Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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- 29 9月, 2014 1 次提交
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由 Vladimir Murzin 提交于
On some platforms with no power management capabilities, the hotplug implementation is allowed to return from a smp_ops.cpu_die() call as a function return. Upon a CPU onlining event, the KVM CPU notifier tries to reinstall the hyp stub, which fails on platform where no reset took place following a hotplug event, with the message: CPU1: smp_ops.cpu_die() returned, trying to resuscitate CPU1: Booted secondary processor Kernel panic - not syncing: unexpected prefetch abort in Hyp mode at: 0x80409540 unexpected data abort in Hyp mode at: 0x80401fe8 unexpected HVC/SVC trap in Hyp mode at: 0x805c6170 since KVM code is trying to reinstall the stub on a system where it is already configured. To prevent this issue, this patch adds a check in the KVM hotplug notifier that detects if the HYP stub really needs re-installing when a CPU is onlined and skips the installation call if the stub is already in place, which means that the CPU has not been reset. Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com> Acked-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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- 26 9月, 2014 2 次提交
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由 Christoffer Dall 提交于
When we catch something that's not a permission fault or a translation fault, we log the unsupported FSC in the kernel log, but we were masking off the bottom bits of the FSC which was not very helpful. Also correctly report the FSC for data and instruction faults rather than telling people it was a DFCS, which doesn't exist in the ARM ARM. Reviewed-by: NPeter Maydell <peter.maydell@linaro.org> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Joel Schopp 提交于
The current aarch64 calculation for VTTBR_BADDR_MASK masks only 39 bits and not all the bits in the PA range. This is clearly a bug that manifests itself on systems that allocate memory in the higher address space range. [ Modified from Joel's original patch to be based on PHYS_MASK_SHIFT instead of a hard-coded value and to move the alignment check of the allocation to mmu.c. Also added a comment explaining why we hardcode the IPA range and changed the stage-2 pgd allocation to be based on the 40 bit IPA range instead of the maximum possible 48 bit PA range. - Christoffer ] Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com> Signed-off-by: NJoel Schopp <joel.schopp@amd.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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- 19 9月, 2014 2 次提交
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由 Marc Zyngier 提交于
It is now quite easy to delay the allocation of the vgic tables until we actually require it to be up and running (when the first vcpu is kicking around, or someones tries to access the GIC registers). This allow us to allocate memory for the exact number of CPUs we have. As nobody configures the number of interrupts just yet, use a fallback to VGIC_NR_IRQS_LEGACY. Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org> Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
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由 Marc Zyngier 提交于
So far, all the VGIC data structures are statically defined by the *maximum* number of vcpus and interrupts it supports. It means that we always have to oversize it to cater for the worse case. Start by changing the data structures to be dynamically sizeable, and allocate them at runtime. The sizes are still very static though. Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
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- 11 9月, 2014 1 次提交
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由 Ard Biesheuvel 提交于
The ISS encoding for an exception from a Data Abort has a WnR bit[6] that indicates whether the Data Abort was caused by a read or a write instruction. While there are several fields in the encoding that are only valid if the ISV bit[24] is set, WnR is not one of them, so we can read it unconditionally. Instead of fixing both implementations of kvm_is_write_fault() in place, reimplement it just once using kvm_vcpu_dabt_iswrite(), which already does the right thing with respect to the WnR bit. Also fix up the callers to pass 'vcpu' Acked-by: NLaszlo Ersek <lersek@redhat.com> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Acked-by: NChristoffer Dall <christoffer.dall@linaro.org> Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
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- 29 8月, 2014 2 次提交
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由 Radim Krčmář 提交于
In the beggining was on_each_cpu(), which required an unused argument to kvm_arch_ops.hardware_{en,dis}able, but this was soon forgotten. Remove unnecessary arguments that stem from this. Signed-off-by: NRadim KrÄmář <rkrcmar@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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由 Radim Krčmář 提交于
Using static inline is going to save few bytes and cycles. For example on powerpc, the difference is 700 B after stripping. (5 kB before) This patch also deals with two overlooked empty functions: kvm_arch_flush_shadow was not removed from arch/mips/kvm/mips.c 2df72e9b KVM: split kvm_arch_flush_shadow and kvm_arch_sched_in never made it into arch/ia64/kvm/kvm-ia64.c. e790d9ef KVM: add kvm_arch_sched_in Signed-off-by: NRadim KrÄmář <rkrcmar@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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- 28 8月, 2014 4 次提交
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由 Will Deacon 提交于
We currently return the number of bytes not copied if set_timer_reg fails, which is almost certainly not what userspace would like. This patch returns -EFAULT instead. Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: NWill Deacon <will.deacon@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Will Deacon 提交于
is_valid_cache returns true if the specified cache is valid. Unfortunately, if the parameter passed it out of range, we return -ENOENT, which ends up as true leading to potential hilarity. This patch returns false on the failure path instead. Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: NWill Deacon <will.deacon@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Will Deacon 提交于
Running sparse results in a bunch of noisy address space mismatches thanks to the broken __percpu annotation on kvm_get_running_vcpus. This function returns a pcpu pointer to a pointer, not a pointer to a pcpu pointer. This patch fixes the annotation, which kills the warnings from sparse. Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: NWill Deacon <will.deacon@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Christoffer Dall 提交于
When userspace loads code and data in a read-only memory regions, KVM needs to be able to handle this on arm and arm64. Specifically this is used when running code directly from a read-only flash device; the common scenario is a UEFI blob loaded with the -bios option in QEMU. Note that the MMIO exit on writes to a read-only memory is ABI and can be used to emulate block-erase style flash devices. Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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- 22 8月, 2014 1 次提交
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由 Radim Krčmář 提交于
Introduce preempt notifiers for architecture specific code. Advantage over creating a new notifier in every arch is slightly simpler code and guaranteed call order with respect to kvm_sched_in. Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
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- 28 7月, 2014 1 次提交
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由 Alexander Graf 提交于
In preparation to make the check_extension function available to VM scope we add a struct kvm * argument to the function header and rename the function accordingly. It will still be called from the /dev/kvm fd, but with a NULL argument for struct kvm *. Signed-off-by: NAlexander Graf <agraf@suse.de> Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
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- 18 7月, 2014 2 次提交
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由 Russell King 提交于
ARMv6 and greater introduced a new instruction ("bx") which can be used to return from function calls. Recent CPUs perform better when the "bx lr" instruction is used rather than the "mov pc, lr" instruction, and this sequence is strongly recommended to be used by the ARM architecture manual (section A.4.1.1). We provide a new macro "ret" with all its variants for the condition code which will resolve to the appropriate instruction. Rather than doing this piecemeal, and miss some instances, change all the "mov pc" instances to use the new macro, with the exception of the "movs" instruction and the kprobes code. This allows us to detect the "mov pc, lr" case and fix it up - and also gives us the possibility of deploying this for other registers depending on the CPU selection. Reported-by: NWill Deacon <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: NShawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
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由 Russell King 提交于
Ensure that platform maintainers check the CPU part number in the right manner: the CPU part number is meaningless without also checking the CPU implement(e|o)r (choose your preferred spelling!) Provide an interface which returns both the implementer and part number together, and update the definitions to include the implementer. Mark the old function as being deprecated... indeed, using the old function with the definitions will now always evaluate as false, so people must update their un-merged code to the new function. While this could be avoided by adding new definitions, we'd also have to create new names for them which would be awkward. Acked-by: NNicolas Pitre <nico@linaro.org> Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
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- 11 7月, 2014 11 次提交
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由 Victor Kamensky 提交于
Previous patches addresses ARMV7 big-endian virtualiztion, kvm related issues, so enable ARM_VIRT_EXT for big-endian now. Signed-off-by: NVictor Kamensky <victor.kamensky@linaro.org> Acked-by: NChristoffer Dall <christoffer.dall@linaro.org> Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
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由 Victor Kamensky 提交于
Fix code that handles KVM_SET_ONE_REG, KVM_GET_ONE_REG ioctls to work in BE image. Before this fix get/set_one_reg functions worked correctly only in LE case - reg_from_user was taking 'void *' kernel address that actually could be target/source memory of either 4 bytes size or 8 bytes size, and code copied from/to user memory that could hold either 4 bytes register, 8 byte register or pair of 4 bytes registers. In order to work in endian agnostic way reg_from_user to reg_to_user functions should copy register value only to kernel variable with size that matches register size. In few place where size mismatch existed fix issue on macro caller side. Signed-off-by: NVictor Kamensky <victor.kamensky@linaro.org> Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org> Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
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由 Victor Kamensky 提交于
The __kvm_vcpu_run function returns a 64-bit result in two registers, which has to be adjusted for BE case. Signed-off-by: NVictor Kamensky <victor.kamensky@linaro.org> Acked-by: NChristoffer Dall <christoffer.dall@linaro.org> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
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由 Victor Kamensky 提交于
In some cases the mcrr and mrrc instructions in combination with the ldrd and strd instructions need to deal with 64bit value in memory. The ldrd and strd instructions already handle endianness within word (register) boundaries but to get effect of the whole 64bit value represented correctly, rr_lo_hi macro is introduced and is used to swap registers positions when the mcrr and mrrc instructions are used. That has the effect of swapping two words. Signed-off-by: NVictor Kamensky <victor.kamensky@linaro.org> Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
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由 Victor Kamensky 提交于
The vgic h/w registers are little endian; when BE asm code reads/writes from/to them, it needs to do byteswap after/before. Byteswap code uses ARM_BE8 wrapper to add swap only if CONFIG_CPU_BIG_ENDIAN is configured. Signed-off-by: NVictor Kamensky <victor.kamensky@linaro.org> Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
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由 Marc Zyngier 提交于
Brutally hack the innocent vgic code, and move the GICv2 specific code to its own file, using vgic_ops and vgic_params as a way to pass information between the two blocks. Acked-by: NCatalin Marinas <catalin.marinas@arm.com> Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org> Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
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由 Marc Zyngier 提交于
In order to make way for the GICv3 registers, move the v2-specific registers to their own structure. Acked-by: NCatalin Marinas <catalin.marinas@arm.com> Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org> Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
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由 Alex Bennée 提交于
For correct guest suspend/resume behaviour we need to ensure we include the generic timer registers for 64 bit guests. As CONFIG_KVM_ARM_TIMER is always set for arm64 we don't need to worry about null implementations. However I have re-jigged the kvm_arm_timer_set/get_reg declarations to be in the common include/kvm/arm_arch_timer.h headers. Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org> Signed-off-by: NAlex Bennée <alex.bennee@linaro.org> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Kim Phillips 提交于
A userspace process can map device MMIO memory via VFIO or /dev/mem, e.g., for platform device passthrough support in QEMU. During early development, we found the PAGE_S2 memory type being used for MMIO mappings. This patch corrects that by using the more strongly ordered memory type for device MMIO mappings: PAGE_S2_DEVICE. Signed-off-by: NKim Phillips <kim.phillips@linaro.org> Acked-by: NChristoffer Dall <christoffer.dall@linaro.org> Acked-by: NWill Deacon <will.deacon@arm.com> Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
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由 Eric Auger 提交于
Currently when a KVM region is deleted or moved after KVM_SET_USER_MEMORY_REGION ioctl, the corresponding intermediate physical memory is not unmapped. This patch corrects this and unmaps the region's IPA range in kvm_arch_commit_memory_region using unmap_stage2_range. Signed-off-by: NEric Auger <eric.auger@linaro.org> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Christoffer Dall 提交于
unmap_range() was utterly broken, to quote Marc, and broke in all sorts of situations. It was also quite complicated to follow and didn't follow the usual scheme of having a separate iterating function for each level of page tables. Address this by refactoring the code and introduce a pgd_clear() function. Reviewed-by: NJungseok Lee <jays.lee@samsung.com> Reviewed-by: NMario Smarduch <m.smarduch@samsung.com> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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- 30 4月, 2014 8 次提交
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由 Anup Patel 提交于
We have PSCI v0.2 emulation available in KVM ARM/ARM64 hence advertise this to user space (i.e. QEMU or KVMTOOL) via KVM_CHECK_EXTENSION ioctl. Signed-off-by: NAnup Patel <anup.patel@linaro.org> Signed-off-by: NPranavkumar Sawargaonkar <pranavkumar@linaro.org> Acked-by: NChristoffer Dall <christoffer.dall@linaro.org> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Anup Patel 提交于
This patch adds emulation of PSCI v0.2 CPU_SUSPEND function call for KVM ARM/ARM64. This is a CPU-level function call which can suspend current CPU or current CPU cluster. We don't have VCPU clusters in KVM so we only suspend the current VCPU. The CPU_SUSPEND emulation is not tested much because currently there is no CPUIDLE driver in Linux kernel that uses PSCI CPU_SUSPEND. The PSCI CPU_SUSPEND implementation in ARM64 kernel was tested using a Simple CPUIDLE driver which is not published due to unstable DT-bindings for PSCI. (For more info, http://lwn.net/Articles/574950/) For simplicity, we implement CPU_SUSPEND emulation similar to WFI (Wait-for-interrupt) emulation and we also treat power-down request to be same as stand-by request. This is consistent with section 5.4.1 and section 5.4.2 of PSCI v0.2 specification. Signed-off-by: NAnup Patel <anup.patel@linaro.org> Signed-off-by: NPranavkumar Sawargaonkar <pranavkumar@linaro.org> Acked-by: NChristoffer Dall <christoffer.dall@linaro.org> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Anup Patel 提交于
As-per PSCI v0.2, the source CPU provides physical address of "entry point" and "context id" for starting a target CPU. Also, if target CPU is already running then we should return ALREADY_ON. Current emulation of CPU_ON function does not consider physical address of "context id" and returns INVALID_PARAMETERS if target CPU is already running. This patch updates kvm_psci_vcpu_on() such that it works for both PSCI v0.1 and PSCI v0.2. Signed-off-by: NAnup Patel <anup.patel@linaro.org> Signed-off-by: NPranavkumar Sawargaonkar <pranavkumar@linaro.org> Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Anup Patel 提交于
This patch adds emulation of PSCI v0.2 MIGRATE, MIGRATE_INFO_TYPE, and MIGRATE_INFO_UP_CPU function calls for KVM ARM/ARM64. KVM ARM/ARM64 being a hypervisor (and not a Trusted OS), we cannot provide this functions hence we emulate these functions in following way: 1. MIGRATE - Returns "Not Supported" 2. MIGRATE_INFO_TYPE - Return 2 i.e. Trusted OS is not present 3. MIGRATE_INFO_UP_CPU - Returns "Not Supported" Signed-off-by: NAnup Patel <anup.patel@linaro.org> Signed-off-by: NPranavkumar Sawargaonkar <pranavkumar@linaro.org> Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Anup Patel 提交于
This patch adds emulation of PSCI v0.2 AFFINITY_INFO function call for KVM ARM/ARM64. This is a VCPU-level function call which will be used to determine current state of given affinity level. Signed-off-by: NAnup Patel <anup.patel@linaro.org> Signed-off-by: NPranavkumar Sawargaonkar <pranavkumar@linaro.org> Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Anup Patel 提交于
The PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET functions are system-level functions hence cannot be fully emulated by in-kernel PSCI emulation code. To tackle this, we forward PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET function calls from vcpu to user space (i.e. QEMU or KVMTOOL) via kvm_run structure using KVM_EXIT_SYSTEM_EVENT exit reasons. Signed-off-by: NAnup Patel <anup.patel@linaro.org> Signed-off-by: NPranavkumar Sawargaonkar <pranavkumar@linaro.org> Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Anup Patel 提交于
Currently, the kvm_psci_call() returns 'true' or 'false' based on whether the PSCI function call was handled successfully or not. This does not help us emulate system-level PSCI functions where the actual emulation work will be done by user space (QEMU or KVMTOOL). Examples of such system-level PSCI functions are: PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET. This patch updates kvm_psci_call() to return three types of values: 1) > 0 (success) 2) = 0 (success but exit to user space) 3) < 0 (errors) Signed-off-by: NAnup Patel <anup.patel@linaro.org> Signed-off-by: NPranavkumar Sawargaonkar <pranavkumar@linaro.org> Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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由 Anup Patel 提交于
Currently, the in-kernel PSCI emulation provides PSCI v0.1 interface to VCPUs. This patch extends current in-kernel PSCI emulation to provide PSCI v0.2 interface to VCPUs. By default, ARM/ARM64 KVM will always provide PSCI v0.1 interface for keeping the ABI backward-compatible. To select PSCI v0.2 interface for VCPUs, the user space (i.e. QEMU or KVMTOOL) will have to set KVM_ARM_VCPU_PSCI_0_2 feature when doing VCPU init using KVM_ARM_VCPU_INIT ioctl. Signed-off-by: NAnup Patel <anup.patel@linaro.org> Signed-off-by: NPranavkumar Sawargaonkar <pranavkumar@linaro.org> Acked-by: NChristoffer Dall <christoffer.dall@linaro.org> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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- 28 4月, 2014 1 次提交
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由 Mark Salter 提交于
The kvm/mmu code shared by arm and arm64 uses kalloc() to allocate a bounce page (if hypervisor init code crosses page boundary) and hypervisor PGDs. The problem is that kalloc() does not guarantee the proper alignment. In the case of the bounce page, the page sized buffer allocated may also cross a page boundary negating the purpose and leading to a hang during kvm initialization. Likewise the PGDs allocated may not meet the minimum alignment requirements of the underlying MMU. This patch uses __get_free_page() to guarantee the worst case alignment needs of the bounce page and PGDs on both arm and arm64. Cc: <stable@vger.kernel.org> # 3.10+ Signed-off-by: NMark Salter <msalter@redhat.com> Acked-by: NMarc Zyngier <marc.zyngier@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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- 26 4月, 2014 1 次提交
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由 Will Deacon 提交于
KVM currently crashes and burns on big-endian hosts, so don't allow it to be selected until we've got that fixed. Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: NWill Deacon <will.deacon@arm.com> Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
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- 20 3月, 2014 1 次提交
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由 Srivatsa S. Bhat 提交于
On 03/15/2014 12:40 AM, Christoffer Dall wrote: > On Fri, Mar 14, 2014 at 11:13:29AM +0530, Srivatsa S. Bhat wrote: >> On 03/13/2014 04:51 AM, Christoffer Dall wrote: >>> On Tue, Mar 11, 2014 at 02:05:38AM +0530, Srivatsa S. Bhat wrote: >>>> Subsystems that want to register CPU hotplug callbacks, as well as perform >>>> initialization for the CPUs that are already online, often do it as shown >>>> below: >>>> [...] >>> Just so we're clear, the existing code was simply racy as not prone to >>> deadlocks, right? > >>> This makes it clear that the test above for compatible CPUs can be quite > >>> easily evaded by using CPU hotplug, but we don't really have a good > >>> solution for handling that yet... Hmmm, grumble grumble, I guess if you > >>> hotplug unsupported CPUs on a KVM/ARM system for now, stuff will break. >> >> In this particular case, there was no deadlock possibility, rather the >> existing code had insufficient synchronization against CPU hotplug. >> >> init_hyp_mode() would invoke cpu_init_hyp_mode() on currently online CPUs >> using on_each_cpu(). If a CPU came online after this point and before calling >> register_cpu_notifier(), that CPU would remain uninitialized because this >> subsystem would miss the hot-online event. This patch fixes this bug and >> also uses the new synchronization method (instead of get/put_online_cpus()) >> to ensure that we don't deadlock with CPU hotplug. >> > > Yes, that was my conclusion as well. Thanks for clarifying. (It could > be noted in the commit message as well if you should feel so inclined). > Please find the patch with updated changelog (and your Ack) below. (No changes in code). From: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Subject: [PATCH] arm, kvm: Fix CPU hotplug callback registration Subsystems that want to register CPU hotplug callbacks, as well as perform initialization for the CPUs that are already online, often do it as shown below: get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(&foobar_cpu_notifier); put_online_cpus(); This is wrong, since it is prone to ABBA deadlocks involving the cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently with CPU hotplug operations). Instead, the correct and race-free way of performing the callback registration is: cpu_notifier_register_begin(); for_each_online_cpu(cpu) init_cpu(cpu); /* Note the use of the double underscored version of the API */ __register_cpu_notifier(&foobar_cpu_notifier); cpu_notifier_register_done(); In the existing arm kvm code, there is no synchronization with CPU hotplug to avoid missing the hotplug events that might occur after invoking init_hyp_mode() and before calling register_cpu_notifier(). Fix this bug and also use the new synchronization method (instead of get/put_online_cpus()) to ensure that we don't deadlock with CPU hotplug. Cc: Gleb Natapov <gleb@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ingo Molnar <mingo@kernel.org> Acked-by: NPaolo Bonzini <pbonzini@redhat.com> Acked-by: NChristoffer Dall <christoffer.dall@linaro.org> Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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- 03 3月, 2014 1 次提交
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由 Marc Zyngier 提交于
Compiling with THP enabled leads to the following warning: arch/arm/kvm/mmu.c: In function ‘unmap_range’: arch/arm/kvm/mmu.c:177:39: warning: ‘pte’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (kvm_pmd_huge(*pmd) || page_empty(pte)) { ^ Code inspection reveals that these two cases are mutually exclusive, so GCC is a bit overzealous here. Silence it anyway by initializing pte to NULL and testing it later on. Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com> Acked-by: NChristoffer Dall <christoffer.dall@linaro.org>
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