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| author | Marc Zyngier <marc.zyngier@arm.com> | 2017-01-25 12:29:59 +0000 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2017-01-30 13:47:37 +0000 |
| commit | 8f36ebaf21fdae99c091c67e8b6fab33969f2667 (patch) | |
| tree | 19f178720ef8382deb6247a6b4c5c388fe479799 /arch/arm64/include | |
| parent | e363e05e12d76b3311618d442ad545dff4d08728 (diff) | |
| download | linux-8f36ebaf21fdae99c091c67e8b6fab33969f2667.tar.gz linux-8f36ebaf21fdae99c091c67e8b6fab33969f2667.tar.xz | |
arm/arm64: KVM: Enforce unconditional flush to PoC when mapping to stage-2
When we fault in a page, we flush it to the PoC (Point of Coherency)
if the faulting vcpu has its own caches off, so that it can observe
the page we just brought it.
But if the vcpu has its caches on, we skip that step. Bad things
happen when *another* vcpu tries to access that page with its own
caches disabled. At that point, there is no garantee that the
data has made it to the PoC, and we access stale data.
The obvious fix is to always flush to PoC when a page is faulted
in, no matter what the state of the vcpu is.
Cc: stable@vger.kernel.org
Fixes: 2d58b733c876 ("arm64: KVM: force cache clean on page fault when caches are off")
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 6f72fe8b0e3e..6d22017ebbad 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -241,8 +241,7 @@ static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu, { void *va = page_address(pfn_to_page(pfn)); - if (!vcpu_has_cache_enabled(vcpu) || ipa_uncached) - kvm_flush_dcache_to_poc(va, size); + kvm_flush_dcache_to_poc(va, size); if (!icache_is_aliasing()) { /* PIPT */ flush_icache_range((unsigned long)va, |