linux-kernel - Re: [PATCH] KVM: x86/xen: Only write Xen hypercall page for guest writes to MSR

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Message-ID: <173958006311.1187438.11536700176929455.b4-ty@google.com>
Date: Fri, 14 Feb 2025 16:50:41 -0800
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>, Paul Durrant <paul@....org>, 
	David Woodhouse <dwmw2@...radead.org>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	syzbot+cdeaeec70992eca2d920@...kaller.appspotmail.com, 
	Joao Martins <joao.m.martins@...cle.com>
Subject: Re: [PATCH] KVM: x86/xen: Only write Xen hypercall page for guest
 writes to MSR

On Thu, 06 Feb 2025 19:14:19 +0000, David Woodhouse wrote:
> The Xen hypercall page MSR is write-only. When the guest writes an address
> to the MSR, the hypervisor populates the referenced page with hypercall
> functions.
> 
> There is no reason for the host ever to write to the MSR, and it isn't
> even readable.
> 
> [...]

Applied to kvm-x86 xen, thanks!  I'll post v2 of my series on top.

[1/1] KVM: x86/xen: Only write Xen hypercall page for guest writes to MSR
      https://github.com/kvm-x86/linux/commit/3617c0ee7dec

--
https://github.com/kvm-x86/linux/tree/next