From: Philipp Giersfeld <[email protected]> Check whether TDX is enabled on this machine. Instead of using CPUID like AMD SEV, Intel TDX enablement can be verified by reading the MSR (https://cc-enabling.trustedservices.intel.com/intel-tdx-enabling-guide/05/host_os_setup/).
Signed-off-by: Philipp Giersfeld <[email protected]> Signed-off-by: Anton Iacobaeus <[email protected]> --- .../query-machine-capabilities.c | 98 ++++++++++++++++--- src/usr/modules-load.conf | 1 + 2 files changed, 86 insertions(+), 13 deletions(-) diff --git a/src/query-machine-capabilities/query-machine-capabilities.c b/src/query-machine-capabilities/query-machine-capabilities.c index 0c522afc..33317aca 100644 --- a/src/query-machine-capabilities/query-machine-capabilities.c +++ b/src/query-machine-capabilities/query-machine-capabilities.c @@ -4,6 +4,8 @@ #include <sys/stat.h> #include <errno.h> #include <string.h> +#include <unistd.h> +#include <fcntl.h> #define eprintf(...) fprintf(stderr, __VA_ARGS__) @@ -18,17 +20,56 @@ typedef struct { uint8_t cbitpos; uint8_t reduced_phys_bits; -} cpu_caps_t; +} cpu_caps_amd_sev_t; -void query_cpu_capabilities(cpu_caps_t *res) { +typedef struct { + bool tdx_support; +} cpu_caps_intel_tdx_t; + +int read_msr(uint32_t msr_index, uint64_t *value) { + uint64_t data; + char* msr_file_name = "/dev/cpu/0/msr"; + int fd; + + fd = open(msr_file_name, O_RDONLY); + if (fd < 0) { + if (errno == ENXIO) { + eprintf("rdmsr: No CPU 0\n"); + return -1; + } else if (errno == EIO) { + eprintf("rdmsr: CPU doesn't support MSRs\n"); + return -1; + } else { + perror("rdmsr: failed to open MSR"); + return -1; + } + } + + if (pread(fd, &data, sizeof(data), msr_index) != sizeof(data)) { + if (errno == EIO) { + eprintf("rdmsr: CPU cannot read MSR 0x%08x\n", msr_index); + return -1; + } else { + perror("rdmsr: pread"); + return -1; + } + } + + *value = data; + + close(fd); + return 0; +} + +void query_cpu_capabilities_sev(cpu_caps_amd_sev_t *res) { uint32_t eax, ebx, ecx, edx; // query Encrypted Memory Capabilities, see: // https://en.wikipedia.org/wiki/CPUID#EAX=8000001Fh:_Encrypted_Memory_Capabilities uint32_t query_function = 0x8000001F; asm volatile("cpuid" - : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx) - : "0"(query_function) + : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx) + : "0"(query_function) ); res->sev_support = (eax & (1<<1)) != 0; @@ -39,6 +80,19 @@ void query_cpu_capabilities(cpu_caps_t *res) { res->reduced_phys_bits = (ebx >> 6) & 0x3f; } +int query_cpu_capabilities_tdx(cpu_caps_intel_tdx_t *res) { + uint64_t tme_value, sgx_value, tdx_value; + + if (read_msr(0x982, &tme_value) == 0 && read_msr(0xa0, &sgx_value) == 0 && + read_msr(0x1401, &tdx_value) == 0) { + res->tdx_support = ((tme_value >> 1) & 1ULL) & (!sgx_value) & ((tdx_value >> 11) & 1ULL); + } else { + eprintf("Intel TDX support undetermined\n"); + return -1; + } + return 0; +} + int prepare_output_directory() { // Check that the directory exists and create it if it does not. struct stat statbuf; @@ -65,8 +119,8 @@ int main() { return 1; } - cpu_caps_t caps; - query_cpu_capabilities(&caps); + cpu_caps_amd_sev_t caps_sev; + query_cpu_capabilities_sev(&caps_sev); FILE *file = fopen(OUTPUT_PATH, "w"); if (file == NULL) { @@ -82,18 +136,36 @@ int main() { " \"sev-support\": %s," " \"sev-support-es\": %s," " \"sev-support-snp\": %s" - " }" - " }\n", - caps.cbitpos, - caps.reduced_phys_bits, - caps.sev_support ? "true" : "false", - caps.sev_es_support ? "true" : "false", - caps.sev_snp_support ? "true" : "false" + " }", + caps_sev.cbitpos, + caps_sev.reduced_phys_bits, + caps_sev.sev_support ? "true" : "false", + caps_sev.sev_es_support ? "true" : "false", + caps_sev.sev_snp_support ? "true" : "false" ); if (ret < 0) { eprintf("Error writing to file '" OUTPUT_PATH "': %s\n", strerror(errno)); } + cpu_caps_intel_tdx_t caps_tdx; + if (query_cpu_capabilities_tdx(&caps_tdx) == 0) { + ret = fprintf(file, + "," + " \"intel-tdx\": {" + " \"tdx-support\": %s" + " }", + caps_tdx.tdx_support ? "true" : "false" + ); + if (ret < 0) { + eprintf("Error writing to file '" OUTPUT_PATH "': %s\n", strerror(errno)); + } + } + + ret = fprintf(file, " }\n"); + if (ret < 0) { + eprintf("Error writing to file '" OUTPUT_PATH "': %s\n", strerror(errno)); + } + ret = fclose(file); if (ret != 0) { eprintf("Error closing file '" OUTPUT_PATH "': %s\n", strerror(errno)); diff --git a/src/usr/modules-load.conf b/src/usr/modules-load.conf index aee7d42a..f45d256b 100644 --- a/src/usr/modules-load.conf +++ b/src/usr/modules-load.conf @@ -1 +1,2 @@ vhost_net +msr -- 2.43.0 _______________________________________________ pve-devel mailing list [email protected] https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
