From: Xin Li <xin3.li@xxxxxxxxx>
Initialize host VMCS FRED fields with host FRED MSRs' value and
guest VMCS FRED fields to 0.
FRED CPU states are managed in 9 new FRED MSRs, as well as a few
existing CPU registers and MSRs, e.g., CR4.FRED. To support FRED
context management, new VMCS fields corresponding to most of FRED
CPU state MSRs are added to both the host-state and guest-state
areas of VMCS.
Specifically no VMCS fields are added for FRED RSP0 and SSP0 MSRs,
because the 2 FRED MSRs are used during ring 3 event delivery only,
thus KVM can run safely even with guest FRED RSP0 and SSP0. Thus
save and restore of FRED RSP0 and SSP0 are deferred.
Signed-off-by: Xin Li <xin3.li@xxxxxxxxx>
Signed-off-by: Xin Li (Intel) <xin@xxxxxxxxx>
Tested-by: Shan Kang <shan.kang@xxxxxxxxx>
---
Change since v2:
* Use structure kvm_host_values to keep host fred config & stack levels
(Sean Christopherson).
Changes since v1:
* Use kvm_cpu_cap_has() instead of cpu_feature_enabled() to decouple
KVM's capability to virtualize a feature and host's enabling of a
feature (Chao Gao).
* Move guest FRED states init into __vmx_vcpu_reset() (Chao Gao).
---
arch/x86/include/asm/vmx.h | 16 ++++++++++++++++
arch/x86/kvm/vmx/vmx.c | 34 ++++++++++++++++++++++++++++++++++
arch/x86/kvm/x86.h | 3 +++
3 files changed, 53 insertions(+)
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 551f62892e1a..5184e03945dd 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -289,12 +289,28 @@ 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_RSP1 = 0x0000281c,
+ GUEST_IA32_FRED_RSP2 = 0x0000281e,
+ GUEST_IA32_FRED_RSP3 = 0x00002820,
+ GUEST_IA32_FRED_STKLVLS = 0x00002822,
+ GUEST_IA32_FRED_SSP1 = 0x00002824,
+ GUEST_IA32_FRED_SSP2 = 0x00002826,
+ GUEST_IA32_FRED_SSP3 = 0x00002828,
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_RSP1 = 0x00002c0a,
+ HOST_IA32_FRED_RSP2 = 0x00002c0c,
+ HOST_IA32_FRED_RSP3 = 0x00002c0e,
+ HOST_IA32_FRED_STKLVLS = 0x00002c10,
+ HOST_IA32_FRED_SSP1 = 0x00002c12,
+ HOST_IA32_FRED_SSP2 = 0x00002c14,
+ HOST_IA32_FRED_SSP3 = 0x00002c16,
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 9b4c30db911f..fee0df93e07c 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1503,6 +1503,18 @@ void vmx_vcpu_load_vmcs(struct kvm_vcpu *vcpu, int cpu,
(unsigned long)(cpu_entry_stack(cpu) + 1));
}
+ /* Per-CPU FRED MSRs */
+ if (kvm_cpu_cap_has(X86_FEATURE_FRED)) {
+#ifdef CONFIG_X86_64
+ vmcs_write64(HOST_IA32_FRED_RSP1, __this_cpu_ist_top_va(DB));
+ vmcs_write64(HOST_IA32_FRED_RSP2, __this_cpu_ist_top_va(NMI));
+ vmcs_write64(HOST_IA32_FRED_RSP3, __this_cpu_ist_top_va(DF));
+#endif
+ vmcs_write64(HOST_IA32_FRED_SSP1, 0);
+ vmcs_write64(HOST_IA32_FRED_SSP2, 0);
+ vmcs_write64(HOST_IA32_FRED_SSP3, 0);
+ }
+
vmx->loaded_vmcs->cpu = cpu;
}
}
@@ -4366,6 +4378,12 @@ void vmx_set_constant_host_state(struct vcpu_vmx *vmx)
*/
vmcs_write16(HOST_DS_SELECTOR, 0);
vmcs_write16(HOST_ES_SELECTOR, 0);
+
+ /* FRED CONFIG and STKLVLS are the same on all CPUs. */
+ if (kvm_cpu_cap_has(X86_FEATURE_FRED)) {
+ vmcs_write64(HOST_IA32_FRED_CONFIG, kvm_host.fred_config);
+ vmcs_write64(HOST_IA32_FRED_STKLVLS, kvm_host.fred_stklvls);
+ }
#else
vmcs_write16(HOST_DS_SELECTOR, __KERNEL_DS); /* 22.2.4 */
vmcs_write16(HOST_ES_SELECTOR, __KERNEL_DS); /* 22.2.4 */
@@ -4876,6 +4894,17 @@ static void init_vmcs(struct vcpu_vmx *vmx)
}
vmx_setup_uret_msrs(vmx);
+
+ if (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)
@@ -8614,6 +8643,11 @@ __init int vmx_hardware_setup(void)
kvm_set_posted_intr_wakeup_handler(pi_wakeup_handler);
+ if (kvm_cpu_cap_has(X86_FEATURE_FRED)) {
+ rdmsrl(MSR_IA32_FRED_CONFIG, kvm_host.fred_config);
+ rdmsrl(MSR_IA32_FRED_STKLVLS, kvm_host.fred_stklvls);
+ }
+
return r;
}
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index a84c48ef5278..578fea05ff18 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -45,6 +45,9 @@ struct kvm_host_values {
u64 xcr0;
u64 xss;
u64 arch_capabilities;
+
+ u64 fred_config;
+ u64 fred_stklvls;
};
void kvm_spurious_fault(void);
--
2.46.2
