----- junaids@xxxxxxxxxx wrote:
> When using shadow paging mode, map guest PCIDs 1:1 to host PCIDs
> instead
> of mapping them all to PCID 0.
>
> Signed-off-by: Junaid Shahid <junaids@xxxxxxxxxx>
> ---
> arch/x86/kvm/mmu.c | 7 +++++--
> arch/x86/kvm/mmu.h | 14 ++++++++++++++
> 2 files changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index 611ecc37e5d2..d93eba7b8787 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -4037,6 +4037,8 @@ static bool fast_cr3_switch(struct kvm_vcpu
> *vcpu, gpa_t old_cr3)
> swap(mmu->root_hpa, mmu->prev_root_hpa);
>
> if (new_cr3 == mmu->prev_cr3 && VALID_PAGE(mmu->root_hpa)) {
> + unsigned long pcid = kvm_get_active_pcid(vcpu);
> +
> /*
> * It is possible that the cached previous root page is
> * obsolete because of a change in the MMU
> @@ -4048,7 +4050,7 @@ static bool fast_cr3_switch(struct kvm_vcpu
> *vcpu, gpa_t old_cr3)
> kvm_mmu_sync_roots(vcpu);
> __clear_sp_write_flooding_count(
> page_header(mmu->root_hpa));
> - mmu->set_cr3(vcpu, mmu->root_hpa, false);
> + mmu->set_cr3(vcpu, mmu->root_hpa | pcid, false);
> return true;
> }
> }
> @@ -4765,6 +4767,7 @@ EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
> int kvm_mmu_load(struct kvm_vcpu *vcpu)
> {
> int r;
> + unsigned long pcid = kvm_get_active_pcid(vcpu);
>
> r = mmu_topup_memory_caches(vcpu);
> if (r)
> @@ -4774,7 +4777,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
> if (r)
> goto out;
> /* set_cr3() should ensure TLB has been flushed */
> - vcpu->arch.mmu.set_cr3(vcpu, vcpu->arch.mmu.root_hpa, false);
> + vcpu->arch.mmu.set_cr3(vcpu, vcpu->arch.mmu.root_hpa | pcid,
> false);
> out:
> return r;
> }
> diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
> index 5b408c0ad612..336fcff60091 100644
> --- a/arch/x86/kvm/mmu.h
> +++ b/arch/x86/kvm/mmu.h
> @@ -85,6 +85,20 @@ static inline int kvm_mmu_reload(struct kvm_vcpu
> *vcpu)
> return kvm_mmu_load(vcpu);
> }
>
> +static inline unsigned long kvm_get_pcid(struct kvm_vcpu *vcpu, gpa_t
> cr3)
> +{
> + BUILD_BUG_ON((X86_CR3_PCID_MASK & PAGE_MASK) != 0);
> +
> + return kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE)
> + ? cr3 & X86_CR3_PCID_MASK
> + : 0;
> +}
> +
> +static inline unsigned long kvm_get_active_pcid(struct kvm_vcpu
> *vcpu)
> +{
> + return kvm_get_pcid(vcpu, kvm_read_cr3(vcpu));
> +}
> +
> /*
> * Currently, we have two sorts of write-protection, a) the first
> one
> * write-protects guest page to sync the guest modification, b)
> another one is
> --
> 2.17.0.441.gb46fe60e1d-goog
Reviewed-by: Liran Alon <liran.alon@xxxxxxxxxx>
