diff options
| author | Saurabh Sengar <ssengar@linux.microsoft.com> | 2024-01-15 09:57:40 -0800 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2024-03-01 08:36:22 +0000 |
| commit | 0d63e4c0ebc2b5c329babde44fd61d3f08db814d (patch) | |
| tree | 813562678ea82cbe4b7037568837ada3a30653cb /arch | |
| parent | 0f34d11234868dc979730a905717c15067a7d205 (diff) | |
x86/hyperv: Allow 15-bit APIC IDs for VTL platforms
The current method for signaling the compatibility of a Hyper-V host
with MSIs featuring 15-bit APIC IDs relies on a synthetic cpuid leaf.
However, for higher VTLs, this leaf is not reported, due to the absence
of an IO-APIC.
As an alternative, assume that when running at a high VTL, the host
supports 15-bit APIC IDs. This assumption is safe, as Hyper-V does not
employ any architectural MSIs at higher VTLs
This unblocks startup of VTL2 environments with more than 256 CPUs.
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/1705341460-18394-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1705341460-18394-1-git-send-email-ssengar@linux.microsoft.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/hyperv/hv_vtl.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c index 96e6c51515f5..cf1b78cb2d04 100644 --- a/arch/x86/hyperv/hv_vtl.c +++ b/arch/x86/hyperv/hv_vtl.c @@ -16,6 +16,11 @@ extern struct boot_params boot_params; static struct real_mode_header hv_vtl_real_mode_header; +static bool __init hv_vtl_msi_ext_dest_id(void) +{ + return true; +} + void __init hv_vtl_init_platform(void) { pr_info("Linux runs in Hyper-V Virtual Trust Level\n"); @@ -38,6 +43,8 @@ void __init hv_vtl_init_platform(void) x86_platform.legacy.warm_reset = 0; x86_platform.legacy.reserve_bios_regions = 0; x86_platform.legacy.devices.pnpbios = 0; + + x86_init.hyper.msi_ext_dest_id = hv_vtl_msi_ext_dest_id; } static inline u64 hv_vtl_system_desc_base(struct ldttss_desc *desc) |