diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2024-11-04 12:38:03 +0200 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2024-11-07 10:27:45 -0800 |
| commit | 7ae15e2f69bad06527668b478dff7c099ad2e6ae (patch) | |
| tree | 6d55e10d139bce8cda15592b9b36440876a4c8d0 | |
| parent | f65aa0ad79fca4ace921da0701644f020129043d (diff) | |
| download | linux-7ae15e2f69bad06527668b478dff7c099ad2e6ae.tar.gz linux-7ae15e2f69bad06527668b478dff7c099ad2e6ae.tar.bz2 linux-7ae15e2f69bad06527668b478dff7c099ad2e6ae.zip | |
x86/tdx: Enable CPU topology enumeration
TDX 1.0 defines baseline behaviour of TDX guest platform. TDX 1.0
generates a #VE when accessing topology-related CPUID leafs (0xB and
0x1F) and the X2APIC_APICID MSR. The kernel returns all zeros on CPUID
topology. In practice, this means that the kernel can only boot with a
plain topology. Any complications will cause problems.
The ENUM_TOPOLOGY feature allows the VMM to provide topology
information to the guest. Enabling the feature eliminates
topology-related #VEs: the TDX module virtualizes accesses to
the CPUID leafs and the MSR.
Enable ENUM_TOPOLOGY if it is available.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/all/20241104103803.195705-5-kirill.shutemov%40linux.intel.com
| -rw-r--r-- | arch/x86/coco/tdx/tdx.c | 27 | ||||
| -rw-r--r-- | arch/x86/include/asm/shared/tdx.h | 2 |
2 files changed, 29 insertions, 0 deletions
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index 2f85ed005c42..0d9b090b4880 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -248,6 +248,32 @@ static void disable_sept_ve(u64 td_attr) TD_CTLS_PENDING_VE_DISABLE); } +/* + * TDX 1.0 generates a #VE when accessing topology-related CPUID leafs (0xB and + * 0x1F) and the X2APIC_APICID MSR. The kernel returns all zeros on CPUID #VEs. + * In practice, this means that the kernel can only boot with a plain topology. + * Any complications will cause problems. + * + * The ENUM_TOPOLOGY feature allows the VMM to provide topology information. + * Enabling the feature eliminates topology-related #VEs: the TDX module + * virtualizes accesses to the CPUID leafs and the MSR. + * + * Enable ENUM_TOPOLOGY if it is available. + */ +static void enable_cpu_topology_enumeration(void) +{ + u64 configured; + + /* Has the VMM provided a valid topology configuration? */ + tdg_vm_rd(TDCS_TOPOLOGY_ENUM_CONFIGURED, &configured); + if (!configured) { + pr_err("VMM did not configure X2APIC_IDs properly\n"); + return; + } + + tdg_vm_wr(TDCS_TD_CTLS, TD_CTLS_ENUM_TOPOLOGY, TD_CTLS_ENUM_TOPOLOGY); +} + static void tdx_setup(u64 *cc_mask) { struct tdx_module_args args = {}; @@ -279,6 +305,7 @@ static void tdx_setup(u64 *cc_mask) tdg_vm_wr(TDCS_NOTIFY_ENABLES, 0, -1ULL); disable_sept_ve(td_attr); + enable_cpu_topology_enumeration(); } /* diff --git a/arch/x86/include/asm/shared/tdx.h b/arch/x86/include/asm/shared/tdx.h index fecb2a6e864b..89f7fcade8ae 100644 --- a/arch/x86/include/asm/shared/tdx.h +++ b/arch/x86/include/asm/shared/tdx.h @@ -23,12 +23,14 @@ #define TDCS_CONFIG_FLAGS 0x1110000300000016 #define TDCS_TD_CTLS 0x1110000300000017 #define TDCS_NOTIFY_ENABLES 0x9100000000000010 +#define TDCS_TOPOLOGY_ENUM_CONFIGURED 0x9100000000000019 /* TDCS_CONFIG_FLAGS bits */ #define TDCS_CONFIG_FLEXIBLE_PENDING_VE BIT_ULL(1) /* TDCS_TD_CTLS bits */ #define TD_CTLS_PENDING_VE_DISABLE BIT_ULL(0) +#define TD_CTLS_ENUM_TOPOLOGY BIT_ULL(1) /* TDX hypercall Leaf IDs */ #define TDVMCALL_MAP_GPA 0x10001 |