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 5.10-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-5.10 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-5.10/kvm-arm64-fix-range-alignment-when-walking-page-tables.patch
queue-5.10/arm64-mm-use-a-48-bit-id-map-when-possible-on-52-bit.patch
queue-5.10/arm64-mte-map-hotplugged-memory-as-normal-tagged.patch
queue-5.10/kvm-arm64-nvhe-save-the-spe-context-early.patch
queue-5.10/arm64-perf-fix-64-bit-event-counter-read-truncation.patch
queue-5.10/arm64-mm-fix-pfn_valid-for-zone_device-based-memory.patch
queue-5.10/mm-userfaultfd-fix-memory-corruption-due-to-writeprotect.patch
queue-5.10/kvm-arm64-avoid-corrupting-vcpu-context-register-in-guest-exit.patch
queue-5.10/arm64-kasan-fix-page_alloc-tagging-with-debug_virtual.patch
