From: Marcelo Tosatti <mtosatti@redhat.com>
To: Nadav Amit <namit@cs.technion.ac.il>
Cc: gleb@kernel.org, pbonzini@redhat.com, tglx@linutronix.de,
mingo@redhat.com, hpa@zytor.com, x86@kernel.org,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: x86: Fix page-tables reserved bits
Date: Wed, 16 Apr 2014 16:03:29 -0300 [thread overview]
Message-ID: <20140416190329.GB8773@amt.cnet> (raw)
In-Reply-To: <1396582264-9864-1-git-send-email-namit@cs.technion.ac.il>
On Fri, Apr 04, 2014 at 06:31:04AM +0300, Nadav Amit wrote:
> KVM does not handle the reserved bits of x86 page tables correctly:
> In PAE, bits 5:8 are reserved in the PDPTE.
> In IA-32e, bit 8 is not reserved.
>
> Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
> ---
> arch/x86/kvm/mmu.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index f5704d9..3993976 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -3538,7 +3538,7 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu,
> case PT32E_ROOT_LEVEL:
> context->rsvd_bits_mask[0][2] =
> rsvd_bits(maxphyaddr, 63) |
> - rsvd_bits(7, 8) | rsvd_bits(1, 2); /* PDPTE */
> + rsvd_bits(5, 8) | rsvd_bits(1, 2); /* PDPTE */
> context->rsvd_bits_mask[0][1] = exb_bit_rsvd |
> rsvd_bits(maxphyaddr, 62); /* PDE */
> context->rsvd_bits_mask[0][0] = exb_bit_rsvd |
> @@ -3550,9 +3550,9 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu,
> break;
> case PT64_ROOT_LEVEL:
> context->rsvd_bits_mask[0][3] = exb_bit_rsvd |
> - rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8);
> + rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 7);
> context->rsvd_bits_mask[0][2] = exb_bit_rsvd |
> - rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8);
> + rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 7);
Bit 7 is not reserved either, for the PDPTE (its PageSize bit).
next prev parent reply other threads:[~2014-04-16 19:04 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-04 3:31 [PATCH] KVM: x86: Fix page-tables reserved bits Nadav Amit
2014-04-16 19:03 ` Marcelo Tosatti [this message]
2014-04-16 21:17 ` H. Peter Anvin
2014-04-16 22:04 ` Marcelo Tosatti
2014-04-28 10:41 ` Paolo Bonzini
2014-04-28 12:20 ` Nadav Amit
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