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Message-ID: <340cf9f24c85b17a1fe752715d95b2c3b84ac700.camel@infradead.org>
Subject: Re: [PATCH 8/8] KVM: xen: automatically use the vcpu_info embedded
 in shared_info
From:   David Woodhouse <dwmw2@infradead.org>
To:     Paul Durrant <paul@xen.org>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     Paul Durrant <pdurrant@amazon.com>,
        Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org
Date:   Thu, 14 Sep 2023 11:09:15 +0200
In-Reply-To: <20230914084946.200043-9-paul@xen.org>
References: <20230914084946.200043-1-paul@xen.org>
         <20230914084946.200043-9-paul@xen.org>
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On Thu, 2023-09-14 at 08:49 +0000, Paul Durrant wrote:
> From: Paul Durrant <pdurrant@amazon.com>
>=20
> Add a KVM_XEN_HVM_CONFIG_DEFAULT_VCPU_INFO flag so that the VMM knows it
> need only set the KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO attribute in response =
to
> a VCPUOP_register_vcpu_info hypercall, and modify get_vcpu_info_cache()
> to pass back a pointer to the shared info pfn cache (and appropriate
> offset) for any of the first 32 vCPUs if the attribute has not been set.

Might be simpler just to link this behaviour to the
KVM_XEN_ATTR_TYPE_SHARED_INFO_HVA support? If userspace sets the
shared_info as an HVA, then the default vcpu_info will be used therein.

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