diff options
Diffstat (limited to 'arch/x86/kernel/cpu/mshyperv.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mshyperv.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index f36dc2f796c5..315fc358e584 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -33,7 +33,6 @@ #include <asm/nmi.h> #include <clocksource/hyperv_timer.h> #include <asm/numa.h> -#include <asm/coco.h> /* Is Linux running as the root partition? */ bool hv_root_partition; @@ -358,12 +357,16 @@ static void __init ms_hyperv_init_platform(void) * To mirror what Windows does we should extract CPU management * features and use the ReservedIdentityBit to detect if Linux is the * root partition. But that requires negotiating CPU management - * interface (a process to be finalized). + * interface (a process to be finalized). For now, use the privilege + * flag as the indicator for running as root. * - * For now, use the privilege flag as the indicator for running as - * root. + * Hyper-V should never specify running as root and as a Confidential + * VM. But to protect against a compromised/malicious Hyper-V trying + * to exploit root behavior to expose Confidential VM memory, ignore + * the root partition setting if also a Confidential VM. */ - if (cpuid_ebx(HYPERV_CPUID_FEATURES) & HV_CPU_MANAGEMENT) { + if ((ms_hyperv.priv_high & HV_CPU_MANAGEMENT) && + !(ms_hyperv.priv_high & HV_ISOLATION)) { hv_root_partition = true; pr_info("Hyper-V: running as root partition\n"); } @@ -397,8 +400,10 @@ static void __init ms_hyperv_init_platform(void) if (ms_hyperv.priv_high & HV_ISOLATION) { ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG); ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG); - ms_hyperv.shared_gpa_boundary = - BIT_ULL(ms_hyperv.shared_gpa_boundary_bits); + + if (ms_hyperv.shared_gpa_boundary_active) + ms_hyperv.shared_gpa_boundary = + BIT_ULL(ms_hyperv.shared_gpa_boundary_bits); pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n", ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b); @@ -409,11 +414,6 @@ static void __init ms_hyperv_init_platform(void) swiotlb_unencrypted_base = ms_hyperv.shared_gpa_boundary; #endif } - /* Isolation VMs are unenlightened SEV-based VMs, thus this check: */ - if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) { - if (hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE) - cc_set_vendor(CC_VENDOR_HYPERV); - } } if (hv_max_functions_eax >= HYPERV_CPUID_NESTED_FEATURES) { @@ -482,6 +482,9 @@ static void __init ms_hyperv_init_platform(void) i8253_clear_counter_on_shutdown = false; #if IS_ENABLED(CONFIG_HYPERV) + if ((hv_get_isolation_type() == HV_ISOLATION_TYPE_VBS) || + (hv_get_isolation_type() == HV_ISOLATION_TYPE_SNP)) + hv_vtom_init(); /* * Setup the hook to get control post apic initialization. */ |