On 05/10/20 17:28, David Woodhouse wrote:
> From: David Woodhouse <dwmw@xxxxxxxxxxxx>
>
> This allows the host to indicate that IOAPIC and MSI emulation supports
> 15-bit destination IDs, allowing up to 32Ki CPUs without remapping.
>
> Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
> ---
> Documentation/virt/kvm/cpuid.rst | 4 ++++
> arch/x86/include/uapi/asm/kvm_para.h | 1 +
> arch/x86/kernel/kvm.c | 6 ++++++
> 3 files changed, 11 insertions(+)
>
> diff --git a/Documentation/virt/kvm/cpuid.rst b/Documentation/virt/kvm/cpuid.rst
> index a7dff9186bed..1726b5925d2b 100644
> --- a/Documentation/virt/kvm/cpuid.rst
> +++ b/Documentation/virt/kvm/cpuid.rst
> @@ -92,6 +92,10 @@ KVM_FEATURE_ASYNC_PF_INT 14 guest checks this feature bit
> async pf acknowledgment msr
> 0x4b564d07.
>
> +KVM_FEATURE_MSI_EXT_DEST_ID 15 guest checks this feature bit
> + before using extended destination
> + ID bits in MSI address bits 11-5.
> +
> KVM_FEATURE_CLOCSOURCE_STABLE_BIT 24 host will warn if no guest-side
> per-cpu warps are expeced in
> kvmclock
> diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
> index 812e9b4c1114..950afebfba88 100644
> --- a/arch/x86/include/uapi/asm/kvm_para.h
> +++ b/arch/x86/include/uapi/asm/kvm_para.h
> @@ -32,6 +32,7 @@
> #define KVM_FEATURE_POLL_CONTROL 12
> #define KVM_FEATURE_PV_SCHED_YIELD 13
> #define KVM_FEATURE_ASYNC_PF_INT 14
> +#define KVM_FEATURE_MSI_EXT_DEST_ID 15
>
> #define KVM_HINTS_REALTIME 0
>
> diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
> index 1b51b727b140..4986b4399aef 100644
> --- a/arch/x86/kernel/kvm.c
> +++ b/arch/x86/kernel/kvm.c
> @@ -743,12 +743,18 @@ static void __init kvm_init_platform(void)
> x86_platform.apic_post_init = kvm_apic_init;
> }
>
> +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.guest_late_init = kvm_guest_init,
> .init.x2apic_available = kvm_para_available,
> + .init.msi_ext_dest_id = kvm_msi_ext_dest_id,
> .init.init_platform = kvm_init_platform,
> };
>
>
Looks like the rest of the series needs some more work, but anyway:
Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Paolo
