From: Paolo Bonzini <pbonzini@redhat.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Ben Gardon <bgardon@google.com>,
Brijesh Singh <brijesh.singh@amd.com>,
Tom Lendacky <thomas.lendacky@amd.com>
Subject: Re: [PATCH v2 11/17] KVM: x86/mmu: Mark the PAE roots as decrypted for shadow paging
Date: Fri, 5 Mar 2021 18:44:18 +0100 [thread overview]
Message-ID: <d18e53f9-f8ce-9793-a3e7-ad945fd1f5f0@redhat.com> (raw)
In-Reply-To: <20210305011101.3597423-12-seanjc@google.com>
On 05/03/21 02:10, Sean Christopherson wrote:
> @@ -5301,6 +5307,22 @@ static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu)
> for (i = 0; i < 4; ++i)
> mmu->pae_root[i] = 0;
I think this should be deleted, since you have another identical for
loop below?
Paolo
> + /*
> + * CR3 is only 32 bits when PAE paging is used, thus it's impossible to
> + * get the CPU to treat the PDPTEs as encrypted. Decrypt the page so
> + * that KVM's writes and the CPU's reads get along. Note, this is
> + * only necessary when using shadow paging, as 64-bit NPT can get at
> + * the C-bit even when shadowing 32-bit NPT, and SME isn't supported
> + * by 32-bit kernels (when KVM itself uses 32-bit NPT).
> + */
> + if (!tdp_enabled)
> + set_memory_decrypted((unsigned long)mmu->pae_root, 1);
> + else
> + WARN_ON_ONCE(shadow_me_mask);
> +
> + for (i = 0; i < 4; ++i)
> + mmu->pae_root[i] = 0;
> +
next prev parent reply other threads:[~2021-03-05 17:45 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-05 1:10 [PATCH v2 00/17] KVM: x86/mmu: Lots of bug fixes Sean Christopherson
2021-03-05 1:10 ` [PATCH v2 01/17] KVM: nSVM: Set the shadow root level to the TDP level for nested NPT Sean Christopherson
2021-03-05 1:10 ` [PATCH v2 02/17] KVM: x86/mmu: Alloc page for PDPTEs when shadowing 32-bit NPT with 64-bit Sean Christopherson
2021-03-05 1:10 ` [PATCH v2 03/17] KVM: x86/mmu: Capture 'mmu' in a local variable when allocating roots Sean Christopherson
2021-03-05 1:10 ` [PATCH v2 04/17] KVM: x86/mmu: Allocate the lm_root before allocating PAE roots Sean Christopherson
2021-03-05 1:10 ` [PATCH v2 05/17] KVM: x86/mmu: Allocate pae_root and lm_root pages in dedicated helper Sean Christopherson
2021-03-05 17:34 ` Paolo Bonzini
2021-03-05 1:10 ` [PATCH v2 06/17] KVM: x86/mmu: Ensure MMU pages are available when allocating roots Sean Christopherson
2021-03-05 1:10 ` [PATCH v2 07/17] KVM: x86/mmu: Check PDPTRs before allocating PAE roots Sean Christopherson
2021-04-08 11:15 ` Wanpeng Li
2021-04-08 12:09 ` Paolo Bonzini
2021-04-08 15:48 ` Sean Christopherson
2021-04-08 15:57 ` Paolo Bonzini
2021-04-08 16:27 ` Sean Christopherson
2021-04-08 16:30 ` Paolo Bonzini
2021-03-05 1:10 ` [PATCH v2 08/17] KVM: x86/mmu: Fix and unconditionally enable WARNs to detect PAE leaks Sean Christopherson
2021-03-05 1:10 ` [PATCH v2 09/17] KVM: x86/mmu: Use '0' as the one and only value for an invalid PAE root Sean Christopherson
2021-03-05 17:52 ` Paolo Bonzini
2021-03-05 18:22 ` Sean Christopherson
2021-03-05 18:23 ` Paolo Bonzini
2021-03-05 1:10 ` [PATCH v2 10/17] KVM: x86/mmu: Set the C-bit in the PDPTRs and LM pseudo-PDPTRs Sean Christopherson
2021-03-05 1:10 ` [PATCH v2 11/17] KVM: x86/mmu: Mark the PAE roots as decrypted for shadow paging Sean Christopherson
2021-03-05 17:44 ` Paolo Bonzini [this message]
2021-03-05 18:02 ` Sean Christopherson
2021-03-05 1:10 ` [PATCH v2 12/17] KVM: SVM: Don't strip the C-bit from CR2 on #PF interception Sean Christopherson
2021-03-05 1:10 ` [PATCH v2 13/17] KVM: nVMX: Defer the MMU reload to the normal path on an EPTP switch Sean Christopherson
2021-03-05 1:10 ` [PATCH v2 14/17] KVM: x86: Defer the MMU unload to the normal path on an global INVPCID Sean Christopherson
2021-03-05 1:10 ` [PATCH v2 15/17] KVM: x86/mmu: Unexport MMU load/unload functions Sean Christopherson
2021-03-05 1:11 ` [PATCH v2 16/17] KVM: x86/mmu: Sync roots after MMU load iff load as successful Sean Christopherson
2021-03-05 1:11 ` [PATCH v2 17/17] KVM: x86/mmu: WARN on NULL pae_root or lm_root, or bad shadow root level Sean Christopherson
2021-03-05 17:53 ` [PATCH v2 00/17] KVM: x86/mmu: Lots of bug fixes Paolo Bonzini
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