* [PATCH] KVM: MMU: Reset mmu->pkru_mask to avoid stale data
@ 2021-10-21 7:10 Chenyi Qiang
2021-10-21 14:53 ` Sean Christopherson
2021-10-21 15:09 ` Paolo Bonzini
0 siblings, 2 replies; 3+ messages in thread
From: Chenyi Qiang @ 2021-10-21 7:10 UTC (permalink / raw)
To: Paolo Bonzini, Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li,
Jim Mattson, Joerg Roedel
Cc: Chenyi Qiang, kvm, linux-kernel
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: commit 2d344105f57c ("KVM, pkeys: introduce pkru_mask to cache conditions")
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
---
arch/x86/kvm/mmu/mmu.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index c6ddb042b281..fe73d7ee5492 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4556,10 +4556,10 @@ 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);
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] KVM: MMU: Reset mmu->pkru_mask to avoid stale data
2021-10-21 7:10 [PATCH] KVM: MMU: Reset mmu->pkru_mask to avoid stale data Chenyi Qiang
@ 2021-10-21 14:53 ` Sean Christopherson
2021-10-21 15:09 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Sean Christopherson @ 2021-10-21 14:53 UTC (permalink / raw)
To: Chenyi Qiang
Cc: Paolo Bonzini, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, kvm, linux-kernel
On Thu, Oct 21, 2021, Chenyi Qiang wrote:
> 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: commit 2d344105f57c ("KVM, pkeys: introduce pkru_mask to cache conditions")
> Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
> ---
Reviewed-by: Sean Christopherson <seanjc@google.com>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] KVM: MMU: Reset mmu->pkru_mask to avoid stale data
2021-10-21 7:10 [PATCH] KVM: MMU: Reset mmu->pkru_mask to avoid stale data Chenyi Qiang
2021-10-21 14:53 ` Sean Christopherson
@ 2021-10-21 15:09 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2021-10-21 15:09 UTC (permalink / raw)
To: Chenyi Qiang, Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li,
Jim Mattson, Joerg Roedel
Cc: kvm, linux-kernel
On 21/10/21 09:10, Chenyi Qiang wrote:
> 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: commit 2d344105f57c ("KVM, pkeys: introduce pkru_mask to cache conditions")
> Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
> ---
> arch/x86/kvm/mmu/mmu.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index c6ddb042b281..fe73d7ee5492 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -4556,10 +4556,10 @@ 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);
>
>
Queued, thanks.
Paolo
^ permalink raw reply [flat|nested] 3+ messages in thread
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Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2021-10-21 7:10 [PATCH] KVM: MMU: Reset mmu->pkru_mask to avoid stale data Chenyi Qiang
2021-10-21 14:53 ` Sean Christopherson
2021-10-21 15:09 ` Paolo Bonzini
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