2024-05-07 16:14:52

by Paolo Bonzini

Subject: [PATCH 15/17] KVM: x86/mmu: Set kvm_page_fault.hva to KVM_HVA_ERR_BAD for "no slot" faults

From: Sean Christopherson <[email protected]>

Explicitly set fault->hva to KVM_HVA_ERR_BAD when handling a "no slot"
fault to ensure that KVM doesn't use a bogus virtual address, e.g. if
there *was* a slot but it's unusable (APIC access page), or if there
really was no slot, in which case fault->hva will be '0' (which is a
legal address for x86).

Signed-off-by: Sean Christopherson <[email protected]>
Reviewed-by: Kai Huang <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
---
arch/x86/kvm/mmu/mmu.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 7630ad8cb022..d717d60c6f19 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3273,6 +3273,7 @@ static int kvm_handle_noslot_fault(struct kvm_vcpu *vcpu,
fault->slot = NULL;
fault->pfn = KVM_PFN_NOSLOT;
fault->map_writable = false;
+ fault->hva = KVM_HVA_ERR_BAD;

/*
* If MMIO caching is disabled, emulate immediately without
--
2.43.0

2024-05-13 06:29:17

by Xiaoyao Li

Subject: Re: [PATCH 15/17] KVM: x86/mmu: Set kvm_page_fault.hva to KVM_HVA_ERR_BAD for "no slot" faults

On 5/7/2024 11:58 PM, Paolo Bonzini wrote:
> From: Sean Christopherson <[email protected]>
>
> Explicitly set fault->hva to KVM_HVA_ERR_BAD when handling a "no slot"
> fault to ensure that KVM doesn't use a bogus virtual address, e.g. if
> there *was* a slot but it's unusable (APIC access page), or if there
> really was no slot, in which case fault->hva will be '0' (which is a
> legal address for x86).
>
> Signed-off-by: Sean Christopherson <[email protected]>
> Reviewed-by: Kai Huang <[email protected]>
> Message-ID: <[email protected]>
> Signed-off-by: Paolo Bonzini <[email protected]>

Reviewed-by: Xiaoyao Li <[email protected]>

> ---
> arch/x86/kvm/mmu/mmu.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 7630ad8cb022..d717d60c6f19 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -3273,6 +3273,7 @@ static int kvm_handle_noslot_fault(struct kvm_vcpu *vcpu,
> fault->slot = NULL;
> fault->pfn = KVM_PFN_NOSLOT;
> fault->map_writable = false;
> + fault->hva = KVM_HVA_ERR_BAD;
>
> /*
> * If MMIO caching is disabled, emulate immediately without