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-Tag: v8.2.0-rc0~23^2~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8473607bcfef62fd8f6bb98b27807bbfce30a81a;p=thirdparty%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>
Reviewed-by: Paul Durrant <paul@xen.org>
---

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 770e81d56e4..11b8177eff2 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -1837,6 +1837,10 @@ 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);