@samitouri / QOSamiQemu / commits / f879d781b4

target/i386/mshv: migrate CET/SS MSRs

This change migrates the MSRs required for CET shadow stack and indirect branch tracking. They are gated behind cet_ss_support || cet_ibt_support mshv processor feature flags. Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com> Link: https://lore.kernel.org/r/20260417105618.3621-24-magnuskulke@linux.microsoft.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Magnus Kulke committed Apr 17, 2026 at 12:56 UTC f879d781b4d8e29ab81db71db6723083c2fe5482
2 files changed +41
include/hw/hyperv/hvgdk_mini.h
+11
@@ -170,6 +170,17 @@ typedef enum hv_register_name {
170 HV_X64_REGISTER_SPEC_CTRL = 0x00080084,
171 HV_X64_REGISTER_TSC_ADJUST = 0x00080096,
172
173 + /* CET / Shadow Stack */
174 + HV_X64_REGISTER_U_XSS = 0x0008008B,
175 + HV_X64_REGISTER_U_CET = 0x0008008C,
176 + HV_X64_REGISTER_S_CET = 0x0008008D,
177 + HV_X64_REGISTER_SSP = 0x0008008E,
178 + HV_X64_REGISTER_PL0_SSP = 0x0008008F,
179 + HV_X64_REGISTER_PL1_SSP = 0x00080090,
180 + HV_X64_REGISTER_PL2_SSP = 0x00080091,
181 + HV_X64_REGISTER_PL3_SSP = 0x00080092,
182 + HV_X64_REGISTER_INTERRUPT_SSP_TABLE_ADDR = 0x00080093,
183 +
184 /* Other MSRs */
185 HV_X64_REGISTER_MSR_IA32_MISC_ENABLE = 0x000800A0,
186
target/i386/mshv/msr.c
+30
@@ -81,6 +81,26 @@ static const MshvMsrEnvMap msr_env_map[] = {
81 { IA32_MSR_MTRR_DEF_TYPE, HV_X64_REGISTER_MSR_MTRR_DEF_TYPE,
82 offsetof(CPUX86State, mtrr_deftype) },
83
84 + /* CET / Shadow Stack */
85 + { MSR_IA32_U_CET, HV_X64_REGISTER_U_CET,
86 + offsetof(CPUX86State, u_cet) },
87 + { MSR_IA32_S_CET, HV_X64_REGISTER_S_CET,
88 + offsetof(CPUX86State, s_cet) },
89 + { MSR_IA32_PL0_SSP, HV_X64_REGISTER_PL0_SSP,
90 + offsetof(CPUX86State, pl0_ssp) },
91 + { MSR_IA32_PL1_SSP, HV_X64_REGISTER_PL1_SSP,
92 + offsetof(CPUX86State, pl1_ssp) },
93 + { MSR_IA32_PL2_SSP, HV_X64_REGISTER_PL2_SSP,
94 + offsetof(CPUX86State, pl2_ssp) },
95 + { MSR_IA32_PL3_SSP, HV_X64_REGISTER_PL3_SSP,
96 + offsetof(CPUX86State, pl3_ssp) },
97 + { MSR_IA32_INT_SSP_TAB, HV_X64_REGISTER_INTERRUPT_SSP_TABLE_ADDR,
98 + offsetof(CPUX86State, int_ssp_table) },
99 +
100 + /* XSAVE Supervisor State */
101 + { MSR_IA32_XSS, HV_X64_REGISTER_U_XSS,
102 + offsetof(CPUX86State, xss) },
103 +
104 /* Other */
105
106 /* TODO: find out processor features that correlate to unsupported MSRs. */
@@ -287,6 +307,16 @@ static bool msr_supported(uint32_t name)
307 return mshv_state->processor_features.ibrs_support;
308 case HV_X64_REGISTER_TSC_ADJUST:
309 return mshv_state->processor_features.tsc_adjust_support;
310 + case HV_X64_REGISTER_U_CET:
311 + case HV_X64_REGISTER_S_CET:
312 + case HV_X64_REGISTER_PL0_SSP:
313 + case HV_X64_REGISTER_PL1_SSP:
314 + case HV_X64_REGISTER_PL2_SSP:
315 + case HV_X64_REGISTER_PL3_SSP:
316 + case HV_X64_REGISTER_INTERRUPT_SSP_TABLE_ADDR:
317 + case HV_X64_REGISTER_U_XSS:
318 + return mshv_state->processor_features.cet_ss_support ||
319 + mshv_state->processor_features.cet_ibt_support;
320 }
321
322 return true;