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2017-04-19KVM: arm/arm64: vgic-v3: De-optimize VMCR save/restore when emulating a GICv2Marc Zyngier
When emulating a GICv2-on-GICv3, special care must be taken to only save/restore VMCR_EL2 when ICC_SRE_EL1.SRE is cleared. Otherwise, all Group-0 interrupts end-up being delivered as FIQ, which is probably not what the guest expects, as demonstrated here with an unhappy EFI: FIQ Exception at 0x000000013BD21CC4 This means that we cannot perform the load/put trick when dealing with VMCR_EL2 (because the host has SRE set), and we have to deal with it in the world-switch. Fortunately, this is not the most common case (modern guests should be able to deal with GICv3 directly), and the performance is not worse than what it was before the VMCR optimization. Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Improve sync_hwstate performanceChristoffer Dall
There is no need to call any functions to fold LRs when we don't use any LRs and we don't need to mess with overflow flags, take spinlocks, or prune the AP list if the AP list is empty. Note: list_empty is a single atomic read (uses READ_ONCE) and can therefore check if a list is empty or not without the need to take the spinlock protecting the list. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Don't check vgic_initialized in sync/flushChristoffer Dall
Now when we do an early init of the static parts of the VGIC data structures, we can do things like checking if the AP lists are empty directly without having to explicitly check if the vgic is initialized and reduce a bit of work in our critical path. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Implement early VGIC init functionalityChristoffer Dall
Implement early initialization for both the distributor and the CPU interfaces. The basic idea is that even though the VGIC is not functional or not requested from user space, the critical path of the run loop can still call VGIC functions that just won't do anything, without them having to check additional initialization flags to ensure they don't look at uninitialized data structures. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Get rid of unnecessary process_maintenance operationChristoffer Dall
Since we always read back the LRs that we wrote to the guest and the MISR and EISR registers simply provide a summary of the configuration of the bits in the LRs, there is really no need to read back those status registers and process them. We might as well just signal the notifyfd when folding the LR state and save some cycles in the process. We now clear the underflow bit in the fold_lr_state functions as we only need to clear this bit if we had used all the LRs, so this is as good a place as any to do that work. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Only set underflow when actually out of LRsChristoffer Dall
We currently assume that all the interrupts in our AP list will be queued to LRs, but that's not necessarily the case, because some of them could have been migrated away to different VCPUs and only the VCPU thread itself can remove interrupts from its AP list. Therefore, slightly change the logic to only setting the underflow interrupt when we actually run out of LRs. As it turns out, this allows us to further simplify the handling in vgic_sync_hwstate in later patches. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Avoid flushing vgic state when there's no pending IRQShih-Wei Li
We do not need to flush vgic states in each world switch unless there is pending IRQ queued to the vgic's ap list. We can thus reduce the overhead by not grabbing the spinlock and not making the extra function call to vgic_flush_lr_state. Note: list_empty is a single atomic read (uses READ_ONCE) and can therefore check if a list is empty or not without the need to take the spinlock protecting the list. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Shih-Wei Li <shihwei@cs.columbia.edu> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/putChristoffer Dall
We don't have to save/restore the VMCR on every entry to/from the guest, since on GICv2 we can access the control interface from EL1 and on VHE systems with GICv3 we can access the control interface from KVM running in EL2. GICv3 systems without VHE becomes the rare case, which has to save/restore the register on each round trip. Note that userspace accesses may see out-of-date values if the VCPU is running while accessing the VGIC state via the KVM device API, but this is already the case and it is up to userspace to quiesce the CPUs before reading the CPU registers from the GIC for an up-to-date view. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-04KVM: arm/arm64: vgic: Fix GICC_PMR uaccess on GICv3 and clarify ABIChristoffer Dall
As an oversight, for GICv2, we accidentally export the GICC_PMR register in the format of the GICH_VMCR.VMPriMask field in the lower 5 bits of a word, meaning that userspace must always use the lower 5 bits to communicate with the KVM device and must shift the value left by 3 places to obtain the actual priority mask level. Since GICv3 supports the full 8 bits of priority masking in the ICH_VMCR, we have to fix the value we export when emulating a GICv2 on top of a hardware GICv3 and exporting the emulated GICv2 state to userspace. Take the chance to clarify this aspect of the ABI. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-04KVM: arm64: Ensure LRs are clear when they should beChristoffer Dall
We currently have some code to clear the list registers on GICv3, but we never call this code, because the caller got nuked when removing the old vgic. We also used to have a similar GICv2 part, but that got lost in the process too. Let's reintroduce the logic for GICv2 and call the logic when we initialize the use of hypervisors on the CPU, for example when first loading KVM or when exiting a low power state. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-03-23arm: kvm: move kvm_vgic_global_state out of .text sectionArd Biesheuvel
The kvm_vgic_global_state struct contains a static key which is written to by jump_label_init() at boot time. So in preparation of making .text regions truly (well, almost truly) read-only, mark kvm_vgic_global_state __ro_after_init so it moves to the .rodata section instead. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Laura Abbott <labbott@redhat.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-03-07KVM: arm/arm64: VGIC: Fix command handling while ITS being disabledAndre Przywara
The ITS spec says that ITS commands are only processed when the ITS is enabled (section 8.19.4, Enabled, bit[0]). Our emulation was not taking this into account. Fix this by checking the enabled state before handling CWRITER writes. On the other hand that means that CWRITER could advance while the ITS is disabled, and enabling it would need those commands to be processed. Fix this case as well by refactoring actual command processing and calling this from both the GITS_CWRITER and GITS_CTLR handlers. Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-03-07KVM: arm/arm64: Let vcpu thread modify its own active stateJintack Lim
Currently, if a vcpu thread tries to change the active state of an interrupt which is already on the same vcpu's AP list, it will loop forever. Since the VGIC mmio handler is called after a vcpu has already synced back the LR state to the struct vgic_irq, we can just let it proceed safely. Cc: stable@vger.kernel.org Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Jintack Lim <jintack@cs.columbia.edu> Signed-off-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-03-06KVM: arm/arm64: vgic-v3: Don't pretend to support IRQ/FIQ bypassMarc Zyngier
Our GICv3 emulation always presents ICC_SRE_EL1 with DIB/DFB set to zero, which implies that there is a way to bypass the GIC and inject raw IRQ/FIQ by driving the CPU pins. Of course, we don't allow that when the GIC is configured, but we fail to indicate that to the guest. The obvious fix is to set these bits (and never let them being changed again). Reported-by: Peter Maydell <peter.maydell@linaro.org> Acked-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-02-08KVM: arm/arm64: vgic: Stop injecting the MSI occurrence twiceShanker Donthineni
The IRQFD framework calls the architecture dependent function twice if the corresponding GSI type is edge triggered. For ARM, the function kvm_set_msi() is getting called twice whenever the IRQFD receives the event signal. The rest of the code path is trying to inject the MSI without any validation checks. No need to call the function vgic_its_inject_msi() second time to avoid an unnecessary overhead in IRQ queue logic. It also avoids the possibility of VM seeing the MSI twice. Simple fix, return -1 if the argument 'level' value is zero. Cc: stable@vger.kernel.org Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-02-01KVM: arm/arm64: Remove kvm_vgic_inject_mapped_irqChristoffer Dall
The only benefit of having kvm_vgic_inject_mapped_irq separate from kvm_vgic_inject_irq is that we pass a boolean that we use for error checking on the injection path. While this could potentially help in some aspect of robustness, it's also a little bit of a defensive move, and arguably callers into the vgic should have make sure they have marked their virtual IRQs as mapped if required. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-01-30KVM: arm/arm64: vgic: Implement KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO ioctlVijaya Kumar K
Userspace requires to store and restore of line_level for level triggered interrupts using ioctl KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-30KVM: arm/arm64: vgic: Implement VGICv3 CPU interface accessVijaya Kumar K
VGICv3 CPU interface registers are accessed using KVM_DEV_ARM_VGIC_CPU_SYSREGS ioctl. These registers are accessed as 64-bit. The cpu MPIDR value is passed along with register id. It is used to identify the cpu for registers access. The VM that supports SEIs expect it on destination machine to handle guest aborts and hence checked for ICC_CTLR_EL1.SEIS compatibility. Similarly, VM that supports Affinity Level 3 that is required for AArch64 mode, is required to be supported on destination machine. Hence checked for ICC_CTLR_EL1.A3V compatibility. The arch/arm64/kvm/vgic-sys-reg-v3.c handles read and write of VGIC CPU registers for AArch64. For AArch32 mode, arch/arm/kvm/vgic-v3-coproc.c file is created but APIs are not implemented. Updated arch/arm/include/uapi/asm/kvm.h with new definitions required to compile for AArch32. The version of VGIC v3 specification is defined here Documentation/virtual/kvm/devices/arm-vgic-v3.txt Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-30KVM: arm/arm64: vgic: Introduce VENG0 and VENG1 fields to vmcr structVijaya Kumar K
ICC_VMCR_EL2 supports virtual access to ICC_IGRPEN1_EL1.Enable and ICC_IGRPEN0_EL1.Enable fields. Add grpen0 and grpen1 member variables to struct vmcr to support read and write of these fields. Also refactor vgic_set_vmcr and vgic_get_vmcr() code. Drop ICH_VMCR_CTLR_SHIFT and ICH_VMCR_CTLR_MASK macros and instead use ICH_VMCR_EOI* and ICH_VMCR_CBPR* macros. Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-30KVM: arm/arm64: vgic: Add distributor and redistributor accessVijaya Kumar K
VGICv3 Distributor and Redistributor registers are accessed using KVM_DEV_ARM_VGIC_GRP_DIST_REGS and KVM_DEV_ARM_VGIC_GRP_REDIST_REGS with KVM_SET_DEVICE_ATTR and KVM_GET_DEVICE_ATTR ioctls. These registers are accessed as 32-bit and cpu mpidr value passed along with register offset is used to identify the cpu for redistributor registers access. The version of VGIC v3 specification is defined here Documentation/virtual/kvm/devices/arm-vgic-v3.txt Also update arch/arm/include/uapi/asm/kvm.h to compile for AArch32 mode. Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-30KVM: arm/arm64: vgic: Implement support for userspace accessVijaya Kumar K
Read and write of some registers like ISPENDR and ICPENDR from userspace requires special handling when compared to guest access for these registers. Refer to Documentation/virtual/kvm/devices/arm-vgic-v3.txt for handling of ISPENDR, ICPENDR registers handling. Add infrastructure to support guest and userspace read and write for the required registers Also moved vgic_uaccess from vgic-mmio-v2.c to vgic-mmio.c Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-25KVM: arm/arm64: vgic: Add debugfs vgic-state fileChristoffer Dall
Add a file to debugfs to read the in-kernel state of the vgic. We don't do any locking of the entire VGIC state while traversing all the IRQs, so if the VM is running the user/developer may not see a quiesced state, but should take care to pause the VM using facilities in user space for that purpose. We also don't support LPIs yet, but they can be added easily if needed. Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-01-25KVM: arm/arm64: Remove struct vgic_irq pending fieldChristoffer Dall
One of the goals behind the VGIC redesign was to get rid of cached or intermediate state in the data structures, but we decided to allow ourselves to precompute the pending value of an IRQ based on the line level and pending latch state. However, this has now become difficult to base proper GICv3 save/restore on, because there is a potential to modify the pending state without knowing if an interrupt is edge or level configured. See the following post and related message for more background: https://lists.cs.columbia.edu/pipermail/kvmarm/2017-January/023195.html This commit gets rid of the precomputed pending field in favor of a function that calculates the value when needed, irq_is_pending(). The soft_pending field is renamed to pending_latch to represent that this latch is the equivalent hardware latch which gets manipulated by the input signal for edge-triggered interrupts and when writing to the SPENDR/CPENDR registers. After this commit save/restore code should be able to simply restore the pending_latch state, line_level state, and config state in any order and get the desired result. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-01-13KVM: arm/arm64: vgic: Fix deadlock on error handlingMarc Zyngier
Dmitry Vyukov reported that the syzkaller fuzzer triggered a deadlock in the vgic setup code when an error was detected, as the cleanup code tries to take a lock that is already held by the setup code. The fix is to avoid retaking the lock when cleaning up, by telling the cleanup function that we already hold it. Cc: stable@vger.kernel.org Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-12-25cpu/hotplug: Cleanup state namesThomas Gleixner
When the state names got added a script was used to add the extra argument to the calls. The script basically converted the state constant to a string, but the cleanup to convert these strings into meaningful ones did not happen. Replace all the useless strings with 'subsys/xxx/yyy:state' strings which are used in all the other places already. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-13Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "Small release, the most interesting stuff is x86 nested virt improvements. x86: - userspace can now hide nested VMX features from guests - nested VMX can now run Hyper-V in a guest - support for AVX512_4VNNIW and AVX512_FMAPS in KVM - infrastructure support for virtual Intel GPUs. PPC: - support for KVM guests on POWER9 - improved support for interrupt polling - optimizations and cleanups. s390: - two small optimizations, more stuff is in flight and will be in 4.11. ARM: - support for the GICv3 ITS on 32bit platforms" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (94 commits) arm64: KVM: pmu: Reset PMSELR_EL0.SEL to a sane value before entering the guest KVM: arm/arm64: timer: Check for properly initialized timer on init KVM: arm/arm64: vgic-v2: Limit ITARGETSR bits to number of VCPUs KVM: x86: Handle the kthread worker using the new API KVM: nVMX: invvpid handling improvements KVM: nVMX: check host CR3 on vmentry and vmexit KVM: nVMX: introduce nested_vmx_load_cr3 and call it on vmentry KVM: nVMX: propagate errors from prepare_vmcs02 KVM: nVMX: fix CR3 load if L2 uses PAE paging and EPT KVM: nVMX: load GUEST_EFER after GUEST_CR0 during emulated VM-entry KVM: nVMX: generate MSR_IA32_CR{0,4}_FIXED1 from guest CPUID KVM: nVMX: fix checks on CR{0,4} during virtual VMX operation KVM: nVMX: support restore of VMX capability MSRs KVM: nVMX: generate non-true VMX MSRs based on true versions KVM: x86: Do not clear RFLAGS.TF when a singlestep trap occurs. KVM: x86: Add kvm_skip_emulated_instruction and use it. KVM: VMX: Move skip_emulated_instruction out of nested_vmx_check_vmcs12 KVM: VMX: Reorder some skip_emulated_instruction calls KVM: x86: Add a return value to kvm_emulate_cpuid KVM: PPC: Book3S: Move prototypes for KVM functions into kvm_ppc.h ...
2016-12-09KVM: arm/arm64: vgic-v2: Limit ITARGETSR bits to number of VCPUsAndre Przywara
The GICv2 spec says in section 4.3.12 that a "CPU targets field bit that corresponds to an unimplemented CPU interface is RAZ/WI." Currently we allow the guest to write any value in there and it can read that back. Mask the written value with the proper CPU mask to be spec compliant. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-11-24KVM: arm/arm64: vgic: Don't notify EOI for non-SPIsMarc Zyngier
When we inject a level triggerered interrupt (and unless it is backed by the physical distributor - timer style), we request a maintenance interrupt. Part of the processing for that interrupt is to feed to the rest of KVM (and to the eventfd subsystem) the information that the interrupt has been EOIed. But that notification only makes sense for SPIs, and not PPIs (such as the PMU interrupt). Skip over the notification if the interrupt is not an SPI. Cc: stable@vger.kernel.org # 4.7+ Fixes: 140b086dd197 ("KVM: arm/arm64: vgic-new: Add GICv2 world switch backend") Fixes: 59529f69f504 ("KVM: arm/arm64: vgic-new: Add GICv3 world switch backend") Reported-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-11-14ARM: KVM: Support vGICv3 ITSVladimir Murzin
This patch allows to build and use vGICv3 ITS in 32-bit mode. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-11-14KVM: arm64: vgic-its: Fix compatibility with 32-bitVladimir Murzin
Evaluate GITS_BASER_ENTRY_SIZE once as an int data (GITS_BASER<n>'s Entry Size is 5-bit wide only), so when used as divider no reference to __aeabi_uldivmod is generated when build for AArch32. Use unsigned long long for GITS_BASER_PAGE_SIZE_* since they are used in conjunction with 64-bit data. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-11-04KVM: arm/arm64: vgic: Kick VCPUs when queueing already pending IRQsShih-Wei Li
In cases like IPI, we could be queueing an interrupt for a VCPU that is already running and is not about to exit, because the VCPU has entered the VM with the interrupt pending and would not trap on EOI'ing that interrupt. This could result to delays in interrupt deliveries or even loss of interrupts. To guarantee prompt interrupt injection, here we have to try to kick the VCPU. Signed-off-by: Shih-Wei Li <shihwei@cs.columbia.edu> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-11-04KVM: arm/arm64: vgic: Prevent access to invalid SPIsAndre Przywara
In our VGIC implementation we limit the number of SPIs to a number that the userland application told us. Accordingly we limit the allocation of memory for virtual IRQs to that number. However in our MMIO dispatcher we didn't check if we ever access an IRQ beyond that limit, leading to out-of-bound accesses. Add a test against the number of allocated SPIs in check_region(). Adjust the VGIC_ADDR_TO_INT macro to avoid an actual division, which is not implemented on ARM(32). [maz: cleaned-up original patch] Cc: stable@vger.kernel.org Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-09-27KVM: arm/arm64: vgic: Don't flush/sync without a working vgicChristoffer Dall
If the vgic hasn't been created and initialized, we shouldn't attempt to look at its data structures or flush/sync anything to the GIC hardware. This fixes an issue reported by Alexander Graf when using a userspace irqchip. Fixes: 0919e84c0fc1 ("KVM: arm/arm64: vgic-new: Add IRQ sync/flush framework") Cc: stable@vger.kernel.org Reported-by: Alexander Graf <agraf@suse.de> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-22ARM: KVM: Support vgic-v3Vladimir Murzin
This patch allows to build and use vgic-v3 in 32-bit mode. Unfortunately, it can not be split in several steps without extra stubs to keep patches independent and bisectable. For instance, virt/kvm/arm/vgic/vgic-v3.c uses function from vgic-v3-sr.c, handling access to GICv3 cpu interface from the guest requires vgic_v3.vgic_sre to be already defined. It is how support has been done: * handle SGI requests from the guest * report configured SRE on access to GICv3 cpu interface from the guest * required vgic-v3 macros are provided via uapi.h * static keys are used to select GIC backend * to make vgic-v3 build KVM_ARM_VGIC_V3 guard is removed along with the static inlines Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-22KVM: arm: vgic: Support 64-bit data manipulation on 32-bit host systemsVladimir Murzin
We have couple of 64-bit registers defined in GICv3 architecture, so unsigned long accesses to these registers will only access a single 32-bit part of that regitser. On the other hand these registers can't be accessed as 64-bit with a single instruction like ldrd/strd or ldmia/stmia if we run a 32-bit host because KVM does not support access to MMIO space done by these instructions. It means that a 32-bit guest accesses these registers in 32-bit chunks, so the only thing we need to do is to ensure that extract_bytes() always takes 64-bit data. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-22KVM: arm: vgic: Fix compiler warnings when built for 32-bitVladimir Murzin
Well, this patch is looking ahead of time, but we'll get following compiler warnings as soon as we introduce vgic-v3 to 32-bit world CC arch/arm/kvm/../../../virt/kvm/arm/vgic/vgic-mmio-v3.o arch/arm/kvm/../../../virt/kvm/arm/vgic/vgic-mmio-v3.c: In function 'vgic_mmio_read_v3r_typer': arch/arm/kvm/../../../virt/kvm/arm/vgic/vgic-mmio-v3.c:184:35: warning: left shift count >= width of type [-Wshift-count-overflow] value = (mpidr & GENMASK(23, 0)) << 32; ^ In file included from ./include/linux/kernel.h:10:0, from ./include/asm-generic/bug.h:13, from ./arch/arm/include/asm/bug.h:59, from ./include/linux/bug.h:4, from ./include/linux/io.h:23, from ./arch/arm/include/asm/arch_gicv3.h:23, from ./include/linux/irqchip/arm-gic-v3.h:411, from arch/arm/kvm/../../../virt/kvm/arm/vgic/vgic-mmio-v3.c:14: arch/arm/kvm/../../../virt/kvm/arm/vgic/vgic-mmio-v3.c: In function 'vgic_v3_dispatch_sgi': ./include/linux/bitops.h:6:24: warning: left shift count >= width of type [-Wshift-count-overflow] #define BIT(nr) (1UL << (nr)) ^ arch/arm/kvm/../../../virt/kvm/arm/vgic/vgic-mmio-v3.c:614:20: note: in expansion of macro 'BIT' broadcast = reg & BIT(ICC_SGI1R_IRQ_ROUTING_MODE_BIT); ^ Let's fix them now. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-22KVM: arm64: vgic-its: Introduce config option to guard ITS specific codeVladimir Murzin
By now ITS code guarded with KVM_ARM_VGIC_V3 config option which was introduced to hide everything specific to vgic-v3 from 32-bit world. We are going to support vgic-v3 in 32-bit world and KVM_ARM_VGIC_V3 will gone, but we don't have support for ITS there yet and we need to continue keeping ITS away. Introduce the new config option to prevent ITS code being build in 32-bit mode when support for vgic-v3 is done. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-22arm64: KVM: Use static keys for selecting the GIC backendVladimir Murzin
Currently GIC backend is selected via alternative framework and this is fine. We are going to introduce vgic-v3 to 32-bit world and there we don't have patching framework in hand, so we can either check support for GICv3 every time we need to choose which backend to use or try to optimise it by using static keys. The later looks quite promising because we can share logic involved in selecting GIC backend between architectures if both uses static keys. This patch moves arm64 from alternative to static keys framework for selecting GIC backend. For that we embed static key into vgic_global and enable the key during vgic initialisation based on what has already been exposed by the host GIC driver. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08arm64: KVM: vgic-v2: Enable GICV access from HYP if access from guest is unsafeMarc Zyngier
So far, we've been disabling KVM on systems where the GICV region couldn't be safely given to a guest. Now that we're able to handle this access safely by emulating it in HYP, we can enable this feature when we detect an unsafe configuration. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08arm64: KVM: vgic-v2: Add the GICV emulation infrastructureMarc Zyngier
In order to efficiently perform the GICV access on behalf of the guest, we need to be able to avoid going back all the way to the host kernel. For this, we introduce a new hook in the world switch code, conveniently placed just after populating the fault info. At that point, we only have saved/restored the GP registers, and we can quickly perform all the required checks (data abort, translation fault, valid faulting syndrome, not an external abort, not a PTW). Coming back from the emulation code, we need to skip the emulated instruction. This involves an additional bit of save/restore in order to be able to access the guest's PC (and possibly CPSR if this is a 32bit guest). At this stage, no emulation code is provided. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08KVM: arm: vgic: Drop build compatibility hack for older kernel versionsMarc Zyngier
As kvm_set_routing_entry() was changing prototype between 4.7 and 4.8, an ugly hack was put in place in order to survive both building in -next and the merge window. Now that everything has been merged, let's dump the compatibility hack for good. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08KVM: arm/arm64: Rename vgic_attr_regs_access to vgic_attr_regs_access_v2Christoffer Dall
Just a rename so we can implement a v3-specific function later. We take the chance to get rid of the V2/V3 ops comments as well. No functional change. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com>
2016-09-08KVM: arm/arm64: Factor out vgic_attr_regs_access functionalityChristoffer Dall
As we are about to deal with multiple data types and situations where the vgic should not be initialized when doing userspace accesses on the register attributes, factor out the functionality of vgic_attr_regs_access into smaller bits which can be reused by a new function later. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com>
2016-08-18Merge tag 'kvm-arm-for-v4.8-rc3' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/ARM Fixes for v4.8-rc3 This tag contains the following fixes on top of v4.8-rc1: - ITS init issues - ITS error handling issues - ITS IRQ leakage fix - Plug a couple of ITS race conditions - An erratum workaround for timers - Some removal of misleading use of errors and comments - A fix for GICv3 on 32-bit guests
2016-08-16KVM: arm64: ITS: avoid re-mapping LPIsAndre Przywara
When a guest wants to map a device-ID/event-ID combination that is already mapped, we may end up in a situation where an LPI is never "put", thus never being freed. Since the GICv3 spec says that mapping an already mapped LPI is UNPREDICTABLE, lets just bail out early in this situation to avoid any potential leaks. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-08-15KVM: arm64: check for ITS device on MSI injectionAndre Przywara
When userspace provides the doorbell address for an MSI to be injected into the guest, we find a KVM device which feels responsible. Lets check that this device is really an emulated ITS before we make real use of the container_of-ed pointer. [ Moved NULL-pointer check to caller of static function - Christoffer ] Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-08-15KVM: arm64: ITS: move ITS registration into first VCPU runAndre Przywara
Currently we register an ITS device upon userland issuing the CTLR_INIT ioctl to mark initialization of the ITS as done. This deviates from the initialization sequence of the existing GIC devices and does not play well with the way QEMU handles things. To be more in line with what we are used to, register the ITS(es) just before the first VCPU is about to run, so in the map_resources() call. This involves iterating through the list of KVM devices and map each ITS that we find. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-08-15KVM: arm64: vgic-its: Make updates to propbaser/pendbaser atomicChristoffer Dall
There are two problems with the current implementation of the MMIO handlers for the propbaser and pendbaser: First, the write to the value itself is not guaranteed to be an atomic 64-bit write so two concurrent writes to the structure field could be intermixed. Second, because we do a read-modify-update operation without any synchronization, if we have two 32-bit accesses to separate parts of the register, we can loose one of them. By using the atomic cmpxchg64 we should cover both issues above. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-08-12KVM: Protect device ops->create and list_add with kvm->lockChristoffer Dall
KVM devices were manipulating list data structures without any form of synchronization, and some implementations of the create operations also suffered from a lack of synchronization. Now when we've split the xics create operation into create and init, we can hold the kvm->lock mutex while calling the create operation and when manipulating the devices list. The error path in the generic code gets slightly ugly because we have to take the mutex again and delete the device from the list, but holding the mutex during anon_inode_getfd or releasing/locking the mutex in the common non-error path seemed wrong. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-08-10KVM: arm64: vgic-its: Plug race in vgic_put_irqChristoffer Dall
Right now the following sequence of events can happen: 1. Thread X calls vgic_put_irq 2. Thread Y calls vgic_add_lpi 3. Thread Y gets lpi_list_lock 4. Thread X drops the ref count to 0 and blocks on lpi_list_lock 5. Thread Y finds the irq via the lpi_list_lock, raises the ref count to 1, and release the lpi_list_lock. 6. Thread X proceeds and frees the irq. Avoid this by holding the spinlock around the kref_put. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>