From: Marcelo Tosatti <mtosatti@redhat.com>
To: Avi Kivity <avi@redhat.com>
Cc: Alexander Graf <agraf@suse.de>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
joerg.roedel@amd.com
Subject: Re: [PATCH] KVM: MMU: Segregate mmu pages created with different cr4.pge settings
Date: Tue, 6 Jan 2009 14:43:11 -0200 [thread overview]
Message-ID: <20090106164311.GA4902@amt.cnet> (raw)
In-Reply-To: <49636AE7.4090108@redhat.com>
On Tue, Jan 06, 2009 at 04:29:59PM +0200, Avi Kivity wrote:
> Yes...
>
> Looks like kvm_unsync_page can be folded into mmu_need_write_protect
> (after which we can drop lookup_page(), which is not a good API). But
> that's after we solve the current problem.
>
> Looks like the addition of a second role for non-pge mode confuses the
> mmu. After the second page is created, mmu_need_write_protect() will
> return 1, but previously existing sptes can still be writable?
>
> Looks like we need to call rmap_write_protect() when the new page is
> created.
I'm not sure about the details, but I suspect that multiple shadows
confuse NPT somehow.
Alexander can you give this a try:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 36aa576..2c6579e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -363,7 +363,8 @@ void kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
}
kvm_x86_ops->set_cr4(vcpu, cr4);
vcpu->arch.cr4 = cr4;
- vcpu->arch.mmu.base_role.cr4_pge = !!(cr4 & X86_CR4_PGE);
+ if (!tdp_enabled)
+ vcpu->arch.mmu.base_role.cr4_pge = !!(cr4 & X86_CR4_PGE);
kvm_mmu_sync_global(vcpu);
kvm_mmu_reset_context(vcpu);
}
next prev parent reply other threads:[~2009-01-06 16:43 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20081221184146.8E00B250012@cleopatra.tlv.redhat.com>
2009-01-05 14:56 ` [PATCH] KVM: MMU: Segregate mmu pages created with different cr4.pge settings Alexander Graf
2009-01-06 10:41 ` Avi Kivity
2009-01-06 14:11 ` Marcelo Tosatti
2009-01-06 14:29 ` Avi Kivity
2009-01-06 15:06 ` Marcelo Tosatti
2009-01-06 16:43 ` Marcelo Tosatti [this message]
2009-01-07 6:49 ` Alexander Graf
2009-01-07 10:19 ` Avi Kivity
2009-01-07 10:43 ` Marcelo Tosatti
2009-01-07 11:32 ` Avi Kivity
2009-01-07 13:46 ` Marcelo Tosatti
2009-01-08 19:53 ` Alexander Graf
2009-01-09 0:36 ` Marcelo Tosatti
2009-01-09 10:43 ` Alexander Graf
2009-01-11 9:12 Marcelo Tosatti
2009-01-11 9:20 ` Avi Kivity
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