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Subject: Re: [PATCH 1/2] KVM: SEV: Pin guest memory for write for
 RECEIVE_UPDATE_DATA
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, Peter Gonda <pgonda@google.com>,
        Marc Orr <marcorr@google.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Brijesh Singh <brijesh.singh@amd.com>,
        Masahiro Kozuka <masa.koz@kozuka.jp>
References: <20210914210951.2994260-1-seanjc@google.com>
 <20210914210951.2994260-2-seanjc@google.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <bdbe4098-a72c-6e73-6f1e-88c2ebc07571@redhat.com>
Date:   Tue, 21 Sep 2021 19:59:16 +0200
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On 14/09/21 23:09, Sean Christopherson wrote:
> Require the target guest page to be writable when pinning memory for
> RECEIVE_UPDATE_DATA.  Per the SEV API, the PSP writes to guest memory:
> 
>    The result is then encrypted with GCTX.VEK and written to the memory
>    pointed to by GUEST_PADDR field.
> 
> Fixes: 15fb7de1a7f5 ("KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command")
> Cc: stable@vger.kernel.org
> Cc: Peter Gonda <pgonda@google.com>
> Cc: Marc Orr <marcorr@google.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: Brijesh Singh <brijesh.singh@amd.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>   arch/x86/kvm/svm/sev.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 75e0b21ad07c..95228ba3cd8f 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -1464,7 +1464,7 @@ static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
>   
>   	/* Pin guest memory */
>   	guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,
> -				    PAGE_SIZE, &n, 0);
> +				    PAGE_SIZE, &n, 1);
>   	if (IS_ERR(guest_page)) {
>   		ret = PTR_ERR(guest_page);
>   		goto e_free_trans;
> 

Queued both, thanks.

Paolo