Messages in this thread | | | Subject | Re: [PATCH] KVM: x86/mmu: preserve pending TLB flush across calls to kvm_tdp_mmu_zap_sp | From | Paolo Bonzini <> | Date | Tue, 6 Apr 2021 20:35:55 +0200 |
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On 06/04/21 20:25, Greg KH wrote: > On Tue, Apr 06, 2021 at 12:25:50PM -0400, Paolo Bonzini wrote: >> Right now, if a call to kvm_tdp_mmu_zap_sp returns false, the caller >> will skip the TLB flush, which is wrong. There are two ways to fix >> it: >> >> - since kvm_tdp_mmu_zap_sp will not yield and therefore will not flush >> the TLB itself, we could change the call to kvm_tdp_mmu_zap_sp to >> use "flush |= ..." >> >> - or we can chain the flush argument through kvm_tdp_mmu_zap_sp down >> to __kvm_tdp_mmu_zap_gfn_range. >> >> This patch does the former to simplify application to stable kernels. >> >> Cc: seanjc@google.com >> Fixes: 048f49809c526 ("KVM: x86/mmu: Ensure TLBs are flushed for TDP MMU during NX zapping") >> Cc: <stable@vger.kernel.org> # 5.10.x: 048f49809c: KVM: x86/mmu: Ensure TLBs are flushed for TDP MMU during NX zapping >> Cc: <stable@vger.kernel.org> # 5.10.x: 33a3164161: KVM: x86/mmu: Don't allow TDP MMU to yield when recovering NX pages >> Cc: <stable@vger.kernel.org> >> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> >> --- >> arch/x86/kvm/mmu/mmu.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) > > Is this for only the stable kernels, or is it addressed toward upstream > merges? > > Confused,
It's for upstream. I'll include it (with the expected "[ Upstream commit abcd ]" header) when I post the complete backport. I'll send this patch to Linus as soon as I get a review even if I don't have anything else in the queue, so (as a general idea) the full backport should be sent and tested on Thursday-Friday.
Paolo
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