From: David Woodhouse <dwmw@amazon.co.uk>
Date: Wed, 11 Oct 2023 22:50:02 +0000 (+0100)
Subject: i386/xen: advertise XEN_HVM_CPUID_UPCALL_VECTOR in CPUID
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=eef6cce89425a575beec45358fa59330b0fdfdc1;p=users%2Fdwmw2%2Fqemu.git

i386/xen: advertise XEN_HVM_CPUID_UPCALL_VECTOR in CPUID

This will allow Linux guests (since v6.0) to use the per-vCPU upcall
vector delivered as MSI through the local APIC.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index f6c7f7e268..8bdbdcdffe 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -1887,6 +1887,10 @@ int kvm_arch_init_vcpu(CPUState *cs)
                 c->eax |= XEN_HVM_CPUID_VCPU_ID_PRESENT;
                 c->ebx = cs->cpu_index;
             }
+
+            if (cs->kvm_state->xen_version >= XEN_VERSION(4, 17)) {
+                c->eax |= XEN_HVM_CPUID_UPCALL_VECTOR;
+            }
         }
 
         r = kvm_xen_init_vcpu(cs);