The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a3ca5281bb771d8103ea16f0a6a8a5df9a7fb4f3 Mon Sep 17 00:00:00 2001

From: Chenyi Qiang chenyi.qiang@intel.com Date: Thu, 21 Oct 2021 15:10:22 +0800 Subject: [PATCH] KVM: MMU: Reset mmu->pkru_mask to avoid stale data

When updating mmu->pkru_mask, the value can only be added but it isn't reset in advance. This will make mmu->pkru_mask keep the stale data. Fix this issue.

Fixes: 2d344105f57c ("KVM, pkeys: introduce pkru_mask to cache conditions") Signed-off-by: Chenyi Qiang chenyi.qiang@intel.com Message-Id: 20211021071022.1140-1-chenyi.qiang@intel.com Reviewed-by: Sean Christopherson seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 1a64ba5b9437..0cc58901bf7a 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4596,10 +4596,10 @@ static void update_pkru_bitmask(struct kvm_mmu *mmu) unsigned bit; bool wp;

- if (!is_cr4_pke(mmu)) { - mmu->pkru_mask = 0; + mmu->pkru_mask = 0; + + if (!is_cr4_pke(mmu)) return; - }

wp = is_cr0_wp(mmu);