diff options
| author | Roger Pau Monne <roger.pau@citrix.com> | 2022-01-20 18:25:27 +0300 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2022-02-10 13:10:17 +0300 |
| commit | e07e98da924e61e814bdaaa3ebc6e72b60dbf9ed (patch) | |
| tree | 2e5604a8522eb851766669509f8921504eae9386 /arch | |
| parent | f34c4f2dd2445ab89e5373fff2990fab36578bd3 (diff) | |
| download | linux-e07e98da924e61e814bdaaa3ebc6e72b60dbf9ed.tar.xz | |
xen/x86: detect support for extended destination ID
Xen allows the usage of some previously reserved bits in the IO-APIC
RTE and the MSI address fields in order to store high bits for the
target APIC ID. Such feature is already implemented by QEMU/KVM and
HyperV, so in order to enable it just add the handler that checks for
it's presence.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20220120152527.7524-3-roger.pau@citrix.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/xen/cpuid.h | 7 | ||||
| -rw-r--r-- | arch/x86/xen/enlighten_hvm.c | 6 |
2 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/include/asm/xen/cpuid.h b/arch/x86/include/asm/xen/cpuid.h index a9630104f1c4..78e667a31d6c 100644 --- a/arch/x86/include/asm/xen/cpuid.h +++ b/arch/x86/include/asm/xen/cpuid.h @@ -100,6 +100,13 @@ /* Memory mapped from other domains has valid IOMMU entries */ #define XEN_HVM_CPUID_IOMMU_MAPPINGS (1u << 2) #define XEN_HVM_CPUID_VCPU_ID_PRESENT (1u << 3) /* vcpu id is present in EBX */ +#define XEN_HVM_CPUID_DOMID_PRESENT (1u << 4) /* domid is present in ECX */ +/* + * Bits 55:49 from the IO-APIC RTE and bits 11:5 from the MSI address can be + * used to store high bits for the Destination ID. This expands the Destination + * ID field from 8 to 15 bits, allowing to target APIC IDs up 32768. + */ +#define XEN_HVM_CPUID_EXT_DEST_ID (1u << 5) /* * Leaf 6 (0x40000x05) diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c index 6448c5071117..945363d9cdba 100644 --- a/arch/x86/xen/enlighten_hvm.c +++ b/arch/x86/xen/enlighten_hvm.c @@ -248,6 +248,11 @@ static __init bool xen_x2apic_available(void) return x2apic_supported(); } +static bool __init msi_ext_dest_id(void) +{ + return cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_EXT_DEST_ID; +} + static __init void xen_hvm_guest_late_init(void) { #ifdef CONFIG_XEN_PVH @@ -310,6 +315,7 @@ struct hypervisor_x86 x86_hyper_xen_hvm __initdata = { .init.x2apic_available = xen_x2apic_available, .init.init_mem_mapping = xen_hvm_init_mem_mapping, .init.guest_late_init = xen_hvm_guest_late_init, + .init.msi_ext_dest_id = msi_ext_dest_id, .runtime.pin_vcpu = xen_pin_vcpu, .ignore_nopv = true, }; |