This is a note to let you know that I've just added the patch titled KVM: arm64: Avoid corrupting vCPU context register in guest exit to the 5.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-arm64-avoid-corrupting-vcpu-context-register-in-guest-exit.patch and it can be found in the queue-5.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 31948332d5fa392ad933f4a6a10026850649ed76 Mon Sep 17 00:00:00 2001 From: Will Deacon <will@xxxxxxxxxx> Date: Fri, 5 Mar 2021 18:52:48 +0000 Subject: KVM: arm64: Avoid corrupting vCPU context register in guest exit From: Will Deacon <will@xxxxxxxxxx> commit 31948332d5fa392ad933f4a6a10026850649ed76 upstream. Commit 7db21530479f ("KVM: arm64: Restore hyp when panicking in guest context") tracks the currently running vCPU, clearing the pointer to NULL on exit from a guest. Unfortunately, the use of 'set_loaded_vcpu' clobbers x1 to point at the kvm_hyp_ctxt instead of the vCPU context, causing the subsequent RAS code to go off into the weeds when it saves the DISR assuming that the CPU context is embedded in a struct vCPU. Leave x1 alone and use x3 as a temporary register instead when clearing the vCPU on the guest exit path. Cc: Marc Zyngier <maz@xxxxxxxxxx> Cc: Andrew Scull <ascull@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Fixes: 7db21530479f ("KVM: arm64: Restore hyp when panicking in guest context") Suggested-by: Quentin Perret <qperret@xxxxxxxxxx> Signed-off-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210226181211.14542-1-will@xxxxxxxxxx Message-Id: <20210305185254.3730990-3-maz@xxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/arm64/kvm/hyp/entry.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -146,7 +146,7 @@ SYM_INNER_LABEL(__guest_exit, SYM_L_GLOB // Now restore the hyp regs restore_callee_saved_regs x2 - set_loaded_vcpu xzr, x1, x2 + set_loaded_vcpu xzr, x2, x3 alternative_if ARM64_HAS_RAS_EXTN // If we have the RAS extensions we can consume a pending error Patches currently in stable-queue which might be from will@xxxxxxxxxx are queue-5.11/kvm-arm64-fix-range-alignment-when-walking-page-tables.patch queue-5.11/arm64-mm-use-a-48-bit-id-map-when-possible-on-52-bit.patch queue-5.11/arm64-mte-map-hotplugged-memory-as-normal-tagged.patch queue-5.11/perf-arm_dmc620_pmu-fix-error-return-code-in-dmc620_.patch queue-5.11/kvm-arm64-nvhe-save-the-spe-context-early.patch queue-5.11/arm64-perf-fix-64-bit-event-counter-read-truncation.patch queue-5.11/kvm-arm64-ensure-i-cache-isolation-between-vcpus-of-a-same-vm.patch queue-5.11/arm64-mm-fix-pfn_valid-for-zone_device-based-memory.patch queue-5.11/mm-userfaultfd-fix-memory-corruption-due-to-writeprotect.patch queue-5.11/kvm-arm64-avoid-corrupting-vcpu-context-register-in-guest-exit.patch queue-5.11/arm64-kasan-fix-page_alloc-tagging-with-debug_virtual.patch