On Mon, Feb 07, 2022 at 06:21:00PM +0000, Jane Malalane wrote:
> diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
> index 7ab15e07a0..4060aef1bd 100644
> --- a/xen/arch/x86/hvm/vmx/vmcs.c
> +++ b/xen/arch/x86/hvm/vmx/vmcs.c
> @@ -343,6 +343,15 @@ static int vmx_init_vmcs_config(bool bsp)
> MSR_IA32_VMX_PROCBASED_CTLS2, &mismatch);
> }
>
> + /* Check whether hardware supports accelerated xapic and x2apic. */
> + if ( bsp )
> + {
> + assisted_xapic_available = cpu_has_vmx_virtualize_apic_accesses;
> + assisted_x2apic_available = (cpu_has_vmx_apic_reg_virt ||
> + cpu_has_vmx_virtual_intr_delivery) &&
> + cpu_has_vmx_virtualize_x2apic_mode;
I've been think about this, and it seems kind of asymmetric that for
xAPIC mode we report hw assisted support only with
virtualize_apic_accesses available, while for x2APIC we require
virtualize_x2apic_mode plus either apic_reg_virt or
virtual_intr_delivery.
I think we likely need to be more consistent here, and report hw
assisted x2APIC support as long as virtualize_x2apic_mode is
available.
This will likely have some effect on patch 2 also, as you will have to
adjust vmx_vlapic_msr_changed.
Thanks, Roger.
