From: David Woodhouse <dwmw@amazon.co.uk>

Date: Wed, 7 Oct 2020 13:20:46 +0100

Subject: [PATCH 5/5] x86/kvm: Add KVM_FEATURE_MSI_EXT_DEST_ID

Patch-mainline: Never, upstream uses different implementation

References: bsc#1181001, jsc#ECO-3191

This allows the host to indicate that IOAPIC and MSI emulation supports

15-bit destination IDs, allowing up to 32768 CPUs without interrupt

remapping.

cf. https://patchwork.kernel.org/patch/11816693/ for qemu

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

Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Acked-by: Joerg Roedel <jroedel@suse.de>

---

 arch/x86/kernel/kvm.c |    6 ++++++

 1 file changed, 6 insertions(+)

--- a/arch/x86/kernel/kvm.c

+++ b/arch/x86/kernel/kvm.c

@@ -578,11 +578,17 @@ static uint32_t __init kvm_detect(void)

 	return kvm_cpuid_base();

 }

+static bool __init kvm_msi_ext_dest_id(void)

+{

+	return kvm_para_has_feature(KVM_FEATURE_MSI_EXT_DEST_ID);

+}

+

 const __initconst struct hypervisor_x86 x86_hyper_kvm = {

 	.name			= "KVM",

 	.detect			= kvm_detect,

 	.type			= X86_HYPER_KVM,

 	.init.x2apic_available	= kvm_para_available,

+	.init.msi_ext_dest_id	= kvm_msi_ext_dest_id,

 };

 static __init int activate_jump_labels(void)