[PATCH] KVM: MMU: Fix regression with ept memory types merged into non-ept page tables
Commit KVM: MMU: Make tdp_enabled a mmu-context parameter made real-mode set -direct_map, and changed the code that merges in the memory type depend on direct_map instead of tdp_enabled. However, in this case what really matters is tdp, not direct_map, since tdp changes the pte format regardless of whether the mapping is direct or not. As a result, real-mode shadow mappings got corrupted with ept memory types. The result was a huge slowdown, likely due to the cache being disabled. Change it back as the simplest fix for the regression (real fix is to move all that to vmx code, and not use tdp_enabled as a synonym for ept). Signed-off-by: Avi Kivity a...@redhat.com --- arch/x86/kvm/mmu.c |2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 6e248d8..3ce56bf 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1980,7 +1980,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, spte |= shadow_user_mask; if (level PT_PAGE_TABLE_LEVEL) spte |= PT_PAGE_SIZE_MASK; - if (vcpu-arch.mmu.direct_map) + if (tdp_enabled) spte |= kvm_x86_ops-get_mt_mask(vcpu, gfn, kvm_is_mmio_pfn(pfn)); -- 1.7.1 -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] KVM: MMU: Fix regression with ept memory types merged into non-ept page tables
On Mon, Sep 13, 2010 at 04:56:19PM +0200, Avi Kivity wrote: Commit KVM: MMU: Make tdp_enabled a mmu-context parameter made real-mode set -direct_map, and changed the code that merges in the memory type depend on direct_map instead of tdp_enabled. However, in this case what really matters is tdp, not direct_map, since tdp changes the pte format regardless of whether the mapping is direct or not. As a result, real-mode shadow mappings got corrupted with ept memory types. The result was a huge slowdown, likely due to the cache being disabled. Change it back as the simplest fix for the regression (real fix is to move all that to vmx code, and not use tdp_enabled as a synonym for ept). Signed-off-by: Avi Kivity a...@redhat.com --- arch/x86/kvm/mmu.c |2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 6e248d8..3ce56bf 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1980,7 +1980,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, spte |= shadow_user_mask; if (level PT_PAGE_TABLE_LEVEL) spte |= PT_PAGE_SIZE_MASK; - if (vcpu-arch.mmu.direct_map) + if (tdp_enabled) spte |= kvm_x86_ops-get_mt_mask(vcpu, gfn, kvm_is_mmio_pfn(pfn)); Oh, indeed. Thanks for fixing this. Acked-by: Joerg Roedel joerg.roe...@amd.com -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
