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Message-ID: <0b55adffa276851ec2c68d1c185d1581d903f2a1.camel@redhat.com>
Subject: Re: [PATCH 1/2] KVM: x86: Add emulation support for #GP triggered
 by VM instructions
From:   Maxim Levitsky <mlevitsk@redhat.com>
To:     Wei Huang <wei.huang2@amd.com>, Andy Lutomirski <luto@kernel.org>,
        Sean Christopherson <seanjc@google.com>
Cc:     kvm list <kvm@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Joerg Roedel <joro@8bytes.org>, Borislav Petkov <bp@alien8.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, X86 ML <x86@kernel.org>,
        Jim Mattson <jmattson@google.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Bandan Das <bsd@redhat.com>,
        "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Date:   Thu, 14 Jan 2021 13:42:06 +0200
In-Reply-To: <0d324a3d-8c33-bb6c-13f3-e60310a54b13@amd.com>
References: <20210112063703.539893-1-wei.huang2@amd.com>
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         <0d324a3d-8c33-bb6c-13f3-e60310a54b13@amd.com>
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On Tue, 2021-01-12 at 23:15 -0600, Wei Huang wrote:
> 
> On 1/12/21 12:58 PM, Andy Lutomirski wrote:
> > Andrew Cooper points out that there may be a nicer workaround.  Make
> > sure that the SMRAM and HT region (FFFD00000000 - FFFFFFFFFFFF) are
> > marked as reserved in the guest, too.
> 
> In theory this proposed solution can avoid intercepting #GP. But in 
> reality SMRAM regions can be different on different machines. So this 
> solution can break after VM migration.
> 
I should add to this, that on my 3970X,
I just noticed that the problematic SMRAM region moved on
its own (likely due to the fact that I moved some pcie cards around recently).

Best regards,
	Maxim Levitsky