From: "Xin Li (Intel)" <[email protected]>
Initialize host VMCS FRED fields with host FRED MSRs' value and
guest VMCS FRED fields to 0.
FRED CPU state is managed in 9 new FRED MSRs:
IA32_FRED_CONFIG,
IA32_FRED_STKLVLS,
IA32_FRED_RSP0,
IA32_FRED_RSP1,
IA32_FRED_RSP2,
IA32_FRED_RSP3,
IA32_FRED_SSP1,
IA32_FRED_SSP2,
IA32_FRED_SSP3,
as well as a few existing CPU registers and MSRs:
CR4.FRED,
IA32_STAR,
IA32_KERNEL_GS_BASE,
IA32_PL0_SSP (also known as IA32_FRED_SSP0).
CR4, IA32_KERNEL_GS_BASE and IA32_STAR are already well managed.
Except IA32_FRED_RSP0 and IA32_FRED_SSP0, all other FRED CPU state
MSRs have corresponding VMCS fields in both the host-state and
guest-state areas. So KVM just needs to initialize them, and with
proper VM entry/exit FRED controls, a FRED CPU will keep tracking
host and guest FRED CPU state in VMCS automatically.
Signed-off-by: Xin Li (Intel) <[email protected]>
Signed-off-by: Sohil Mehta <[email protected]>
Reviewed-by: Chao Gao <[email protected]>
Reviewed-by: Binbin Wu <[email protected]>
---
v10:
- s/rdmsrl/rdmsrq (Chao)
- Remove a terse comment which doesn't help at all (Sean).
- Replace direct, raw use of __this_cpu_ist_top_va() with a self-
explanatory this_cpu_fred_rsp() helper for better readability (Sean).
- Add cpu_feature_enabled(X86_FEATURE_FRED) to patch out accesses to
VMCS FRED fields (Sean).
- Remove "#ifdef CONFIG_X86_64" after switching to this_cpu_fred_rsp()
(Sean).
---
arch/x86/include/asm/kvm_host.h | 3 +++
arch/x86/include/asm/vmx.h | 32 ++++++++++++++++++++++++++++++++
arch/x86/kvm/vmx/vmx.c | 33 +++++++++++++++++++++++++++++++++
3 files changed, 68 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 683bb8bf43a9..8d3999772ac2 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -294,6 +294,9 @@ struct kvm_host_values {
u64 xss;
u64 s_cet;
u64 arch_capabilities;
+
+ u64 fred_config;
+ u64 fred_stklvls;
};
extern struct kvm_host_values kvm_host;
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 682f09933612..4720619f09ac 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -306,12 +306,44 @@ enum vmcs_field {
GUEST_BNDCFGS_HIGH = 0x00002813,
GUEST_IA32_RTIT_CTL = 0x00002814,
GUEST_IA32_RTIT_CTL_HIGH = 0x00002815,
+ GUEST_IA32_FRED_CONFIG = 0x0000281a,
+ GUEST_IA32_FRED_CONFIG_HIGH = 0x0000281b,
+ GUEST_IA32_FRED_RSP1 = 0x0000281c,
+ GUEST_IA32_FRED_RSP1_HIGH = 0x0000281d,
+ GUEST_IA32_FRED_RSP2 = 0x0000281e,
+ GUEST_IA32_FRED_RSP2_HIGH = 0x0000281f,
+ GUEST_IA32_FRED_RSP3 = 0x00002820,
+ GUEST_IA32_FRED_RSP3_HIGH = 0x00002821,
+ GUEST_IA32_FRED_STKLVLS = 0x00002822,
+ GUEST_IA32_FRED_STKLVLS_HIGH = 0x00002823,
+ GUEST_IA32_FRED_SSP1 = 0x00002824,
+ GUEST_IA32_FRED_SSP1_HIGH = 0x00002825,
+ GUEST_IA32_FRED_SSP2 = 0x00002826,
+ GUEST_IA32_FRED_SSP2_HIGH = 0x00002827,
+ GUEST_IA32_FRED_SSP3 = 0x00002828,
+ GUEST_IA32_FRED_SSP3_HIGH = 0x00002829,
HOST_IA32_PAT = 0x00002c00,
HOST_IA32_PAT_HIGH = 0x00002c01,
HOST_IA32_EFER = 0x00002c02,
HOST_IA32_EFER_HIGH = 0x00002c03,
HOST_IA32_PERF_GLOBAL_CTRL = 0x00002c04,
HOST_IA32_PERF_GLOBAL_CTRL_HIGH = 0x00002c05,
+ HOST_IA32_FRED_CONFIG = 0x00002c08,
+ HOST_IA32_FRED_CONFIG_HIGH = 0x00002c09,
+ HOST_IA32_FRED_RSP1 = 0x00002c0a,
+ HOST_IA32_FRED_RSP1_HIGH = 0x00002c0b,
+ HOST_IA32_FRED_RSP2 = 0x00002c0c,
+ HOST_IA32_FRED_RSP2_HIGH = 0x00002c0d,
+ HOST_IA32_FRED_RSP3 = 0x00002c0e,
+ HOST_IA32_FRED_RSP3_HIGH = 0x00002c0f,
+ HOST_IA32_FRED_STKLVLS = 0x00002c10,
+ HOST_IA32_FRED_STKLVLS_HIGH = 0x00002c11,
+ HOST_IA32_FRED_SSP1 = 0x00002c12,
+ HOST_IA32_FRED_SSP1_HIGH = 0x00002c13,
+ HOST_IA32_FRED_SSP2 = 0x00002c14,
+ HOST_IA32_FRED_SSP2_HIGH = 0x00002c15,
+ HOST_IA32_FRED_SSP3 = 0x00002c16,
+ HOST_IA32_FRED_SSP3_HIGH = 0x00002c17,
PIN_BASED_VM_EXEC_CONTROL = 0x00004000,
CPU_BASED_VM_EXEC_CONTROL = 0x00004002,
EXCEPTION_BITMAP = 0x00004004,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 2a2218e0983b..dc80ca5f804d 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1562,6 +1562,12 @@ void vmx_vcpu_load_vmcs(struct kvm_vcpu *vcpu, int cpu)
(unsigned long)(cpu_entry_stack(cpu) + 1));
}
+ if (cpu_feature_enabled(X86_FEATURE_FRED) &&
kvm_cpu_cap_has(X86_FEATURE_FRED)) {
+ vmcs_write64(HOST_IA32_FRED_RSP1,
this_cpu_fred_rsp(FRED_STACK_LEVEL_1));
+ vmcs_write64(HOST_IA32_FRED_RSP2,
this_cpu_fred_rsp(FRED_STACK_LEVEL_2));
+ vmcs_write64(HOST_IA32_FRED_RSP3,
this_cpu_fred_rsp(FRED_STACK_LEVEL_3));
+ }
+
vmx->loaded_vmcs->cpu = cpu;
}
}
@@ -4500,6 +4506,17 @@ void vmx_set_constant_host_state(struct vcpu_vmx *vmx)
*/
vmcs_write16(HOST_DS_SELECTOR, 0);
vmcs_write16(HOST_ES_SELECTOR, 0);
+
+ if (cpu_feature_enabled(X86_FEATURE_FRED) &&
kvm_cpu_cap_has(X86_FEATURE_FRED)) {
+ /* FRED CONFIG and STKLVLS are the same on all CPUs */
+ vmcs_write64(HOST_IA32_FRED_CONFIG, kvm_host.fred_config);
+ vmcs_write64(HOST_IA32_FRED_STKLVLS, kvm_host.fred_stklvls);
+
+ /* Linux doesn't support kernel shadow stacks, thus SSPs are 0s
*/
+ vmcs_write64(HOST_IA32_FRED_SSP1, 0);
+ vmcs_write64(HOST_IA32_FRED_SSP2, 0);
+ vmcs_write64(HOST_IA32_FRED_SSP3, 0);
+ }
#else
vmcs_write16(HOST_DS_SELECTOR, __KERNEL_DS); /* 22.2.4 */
vmcs_write16(HOST_ES_SELECTOR, __KERNEL_DS); /* 22.2.4 */
@@ -5030,6 +5047,17 @@ static void init_vmcs(struct vcpu_vmx *vmx)
}
vmx_setup_uret_msrs(vmx);
+
+ if (cpu_feature_enabled(X86_FEATURE_FRED) &&
kvm_cpu_cap_has(X86_FEATURE_FRED)) {
+ vmcs_write64(GUEST_IA32_FRED_CONFIG, 0);
+ vmcs_write64(GUEST_IA32_FRED_RSP1, 0);
+ vmcs_write64(GUEST_IA32_FRED_RSP2, 0);
+ vmcs_write64(GUEST_IA32_FRED_RSP3, 0);
+ vmcs_write64(GUEST_IA32_FRED_STKLVLS, 0);
+ vmcs_write64(GUEST_IA32_FRED_SSP1, 0);
+ vmcs_write64(GUEST_IA32_FRED_SSP2, 0);
+ vmcs_write64(GUEST_IA32_FRED_SSP3, 0);
+ }
}
static void __vmx_vcpu_reset(struct kvm_vcpu *vcpu)
@@ -8883,6 +8911,11 @@ __init int vmx_hardware_setup(void)
kvm_caps.inapplicable_quirks &= ~KVM_X86_QUIRK_IGNORE_GUEST_PAT;
+ if (cpu_feature_enabled(X86_FEATURE_FRED) &&
kvm_cpu_cap_has(X86_FEATURE_FRED)) {
+ rdmsrq(MSR_IA32_FRED_CONFIG, kvm_host.fred_config);
+ rdmsrq(MSR_IA32_FRED_STKLVLS, kvm_host.fred_stklvls);
+ }
+
return 0;
}
--
2.43.0
