diff options
| -rw-r--r-- | arch/x86/include/asm/msr-index.h | 12 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx.c | 219 |
2 files changed, 231 insertions, 0 deletions
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index 485b4f1f079..e3022ccff33 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -438,6 +438,18 @@ #define MSR_IA32_VMX_VMCS_ENUM 0x0000048a #define MSR_IA32_VMX_PROCBASED_CTLS2 0x0000048b #define MSR_IA32_VMX_EPT_VPID_CAP 0x0000048c +#define MSR_IA32_VMX_TRUE_PINBASED_CTLS 0x0000048d +#define MSR_IA32_VMX_TRUE_PROCBASED_CTLS 0x0000048e +#define MSR_IA32_VMX_TRUE_EXIT_CTLS 0x0000048f +#define MSR_IA32_VMX_TRUE_ENTRY_CTLS 0x00000490 + +/* VMX_BASIC bits and bitmasks */ +#define VMX_BASIC_VMCS_SIZE_SHIFT 32 +#define VMX_BASIC_64 0x0001000000000000LLU +#define VMX_BASIC_MEM_TYPE_SHIFT 50 +#define VMX_BASIC_MEM_TYPE_MASK 0x003c000000000000LLU +#define VMX_BASIC_MEM_TYPE_WB 6LLU +#define VMX_BASIC_INOUT 0x0040000000000000LLU /* AMD-V MSRs */ diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 914dc4e9b37..487952b2021 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1396,6 +1396,218 @@ static inline bool nested_vmx_allowed(struct kvm_vcpu *vcpu) } /* + * nested_vmx_setup_ctls_msrs() sets up variables containing the values to be + * returned for the various VMX controls MSRs when nested VMX is enabled. + * The same values should also be used to verify that vmcs12 control fields are + * valid during nested entry from L1 to L2. + * Each of these control msrs has a low and high 32-bit half: A low bit is on + * if the corresponding bit in the (32-bit) control field *must* be on, and a + * bit in the high half is on if the corresponding bit in the control field + * may be on. See also vmx_control_verify(). + * TODO: allow these variables to be modified (downgraded) by module options + * or other means. + */ +static u32 nested_vmx_procbased_ctls_low, nested_vmx_procbased_ctls_high; +static u32 nested_vmx_secondary_ctls_low, nested_vmx_secondary_ctls_high; +static u32 nested_vmx_pinbased_ctls_low, nested_vmx_pinbased_ctls_high; +static u32 nested_vmx_exit_ctls_low, nested_vmx_exit_ctls_high; +static u32 nested_vmx_entry_ctls_low, nested_vmx_entry_ctls_high; +static __init void nested_vmx_setup_ctls_msrs(void) +{ + /* + * Note that as a general rule, the high half of the MSRs (bits in + * the control fields which may be 1) should be initialized by the + * intersection of the underlying hardware's MSR (i.e., features which + * can be supported) and the list of features we want to expose - + * because they are known to be properly supported in our code. + * Also, usually, the low half of the MSRs (bits which must be 1) can + * be set to 0, meaning that L1 may turn off any of these bits. The + * reason is that if one of these bits is necessary, it will appear + * in vmcs01 and prepare_vmcs02, when it bitwise-or's the control + * fields of vmcs01 and vmcs02, will turn these bits off - and + * nested_vmx_exit_handled() will not pass related exits to L1. + * These rules have exceptions below. + */ + + /* pin-based controls */ + /* + * According to the Intel spec, if bit 55 of VMX_BASIC is off (as it is + * in our case), bits 1, 2 and 4 (i.e., 0x16) must be 1 in this MSR. + */ + nested_vmx_pinbased_ctls_low = 0x16 ; + nested_vmx_pinbased_ctls_high = 0x16 | + PIN_BASED_EXT_INTR_MASK | PIN_BASED_NMI_EXITING | + PIN_BASED_VIRTUAL_NMIS; + + /* exit controls */ + nested_vmx_exit_ctls_low = 0; +#ifdef CONFIG_X86_64 + nested_vmx_exit_ctls_high = VM_EXIT_HOST_ADDR_SPACE_SIZE; +#else + nested_vmx_exit_ctls_high = 0; +#endif + + /* entry controls */ + rdmsr(MSR_IA32_VMX_ENTRY_CTLS, + nested_vmx_entry_ctls_low, nested_vmx_entry_ctls_high); + nested_vmx_entry_ctls_low = 0; + nested_vmx_entry_ctls_high &= + VM_ENTRY_LOAD_IA32_PAT | VM_ENTRY_IA32E_MODE; + + /* cpu-based controls */ + rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, + nested_vmx_procbased_ctls_low, nested_vmx_procbased_ctls_high); + nested_vmx_procbased_ctls_low = 0; + nested_vmx_procbased_ctls_high &= + CPU_BASED_VIRTUAL_INTR_PENDING | CPU_BASED_USE_TSC_OFFSETING | + CPU_BASED_HLT_EXITING | CPU_BASED_INVLPG_EXITING | + CPU_BASED_MWAIT_EXITING | CPU_BASED_CR3_LOAD_EXITING | + CPU_BASED_CR3_STORE_EXITING | +#ifdef CONFIG_X86_64 + CPU_BASED_CR8_LOAD_EXITING | CPU_BASED_CR8_STORE_EXITING | +#endif + CPU_BASED_MOV_DR_EXITING | CPU_BASED_UNCOND_IO_EXITING | + CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_EXITING | + CPU_BASED_ACTIVATE_SECONDARY_CONTROLS; + /* + * We can allow some features even when not supported by the + * hardware. For example, L1 can specify an MSR bitmap - and we + * can use it to avoid exits to L1 - even when L0 runs L2 + * without MSR bitmaps. + */ + nested_vmx_procbased_ctls_high |= CPU_BASED_USE_MSR_BITMAPS; + + /* secondary cpu-based controls */ + rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2, + nested_vmx_secondary_ctls_low, nested_vmx_secondary_ctls_high); + nested_vmx_secondary_ctls_low = 0; + nested_vmx_secondary_ctls_high &= + SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES; +} + +static inline bool vmx_control_verify(u32 control, u32 low, u32 high) +{ + /* + * Bits 0 in high must be 0, and bits 1 in low must be 1. + */ + return ((control & high) | low) == control; +} + +static inline u64 vmx_control_msr(u32 low, u32 high) +{ + return low | ((u64)high << 32); +} + +/* + * If we allow our guest to use VMX instructions (i.e., nested VMX), we should + * also let it use VMX-specific MSRs. + * vmx_get_vmx_msr() and vmx_set_vmx_msr() return 1 when we handled a + * VMX-specific MSR, or 0 when we haven't (and the caller should handle it + * like all other MSRs). + */ +static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata) +{ + if (!nested_vmx_allowed(vcpu) && msr_index >= MSR_IA32_VMX_BASIC && + msr_index <= MSR_IA32_VMX_TRUE_ENTRY_CTLS) { + /* + * According to the spec, processors which do not support VMX + * should throw a #GP(0) when VMX capability MSRs are read. + */ + kvm_queue_exception_e(vcpu, GP_VECTOR, 0); + return 1; + } + + switch (msr_index) { + case MSR_IA32_FEATURE_CONTROL: + *pdata = 0; + break; + case MSR_IA32_VMX_BASIC: + /* + * This MSR reports some information about VMX support. We + * should return information about the VMX we emulate for the + * guest, and the VMCS structure we give it - not about the + * VMX support of the underlying hardware. + */ + *pdata = VMCS12_REVISION | + ((u64)VMCS12_SIZE << VMX_BASIC_VMCS_SIZE_SHIFT) | + (VMX_BASIC_MEM_TYPE_WB << VMX_BASIC_MEM_TYPE_SHIFT); + break; + case MSR_IA32_VMX_TRUE_PINBASED_CTLS: + case MSR_IA32_VMX_PINBASED_CTLS: + *pdata = vmx_control_msr(nested_vmx_pinbased_ctls_low, + nested_vmx_pinbased_ctls_high); + break; + case MSR_IA32_VMX_TRUE_PROCBASED_CTLS: + case MSR_IA32_VMX_PROCBASED_CTLS: + *pdata = vmx_control_msr(nested_vmx_procbased_ctls_low, + nested_vmx_procbased_ctls_high); + break; + case MSR_IA32_VMX_TRUE_EXIT_CTLS: + case MSR_IA32_VMX_EXIT_CTLS: + *pdata = vmx_control_msr(nested_vmx_exit_ctls_low, + nested_vmx_exit_ctls_high); + break; + case MSR_IA32_VMX_TRUE_ENTRY_CTLS: + case MSR_IA32_VMX_ENTRY_CTLS: + *pdata = vmx_control_msr(nested_vmx_entry_ctls_low, + nested_vmx_entry_ctls_high); + break; + case MSR_IA32_VMX_MISC: + *pdata = 0; + break; + /* + * These MSRs specify bits which the guest must keep fixed (on or off) + * while L1 is in VMXON mode (in L1's root mode, or running an L2). + * We picked the standard core2 setting. + */ +#define VMXON_CR0_ALWAYSON (X86_CR0_PE | X86_CR0_PG | X86_CR0_NE) +#define VMXON_CR4_ALWAYSON X86_CR4_VMXE + case MSR_IA32_VMX_CR0_FIXED0: + *pdata = VMXON_CR0_ALWAYSON; + break; + case MSR_IA32_VMX_CR0_FIXED1: + *pdata = -1ULL; + break; + case MSR_IA32_VMX_CR4_FIXED0: + *pdata = VMXON_CR4_ALWAYSON; + break; + case MSR_IA32_VMX_CR4_FIXED1: + *pdata = -1ULL; + break; + case MSR_IA32_VMX_VMCS_ENUM: + *pdata = 0x1f; + break; + case MSR_IA32_VMX_PROCBASED_CTLS2: + *pdata = vmx_control_msr(nested_vmx_secondary_ctls_low, + nested_vmx_secondary_ctls_high); + break; + case MSR_IA32_VMX_EPT_VPID_CAP: + /* Currently, no nested ept or nested vpid */ + *pdata = 0; + break; + default: + return 0; + } + + return 1; +} + +static int vmx_set_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data) +{ + if (!nested_vmx_allowed(vcpu)) + return 0; + + if (msr_index == MSR_IA32_FEATURE_CONTROL) + /* TODO: the right thing. */ + return 1; + /* + * No need to treat VMX capability MSRs specially: If we don't handle + * them, handle_wrmsr will #GP(0), which is correct (they are readonly) + */ + return 0; +} + +/* * Reads an msr value (of 'msr_index') into 'pdata'. * Returns 0 on success, non-0 otherwise. * Assumes vcpu_load() was already called. @@ -1443,6 +1655,8 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata) /* Otherwise falls through */ default: vmx_load_host_state(to_vmx(vcpu)); + if (vmx_get_vmx_msr(vcpu, msr_index, pdata)) + return 0; msr = find_msr_entry(to_vmx(vcpu), msr_index); if (msr) { vmx_load_host_state(to_vmx(vcpu)); @@ -1514,6 +1728,8 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data) return 1; /* Otherwise falls through */ default: + if (vmx_set_vmx_msr(vcpu, msr_index, data)) + break; msr = find_msr_entry(vmx, msr_index); if (msr) { vmx_load_host_state(vmx); @@ -1902,6 +2118,9 @@ static __init int hardware_setup(void) if (!cpu_has_vmx_ple()) ple_gap = 0; + if (nested) + nested_vmx_setup_ctls_msrs(); + return alloc_kvm_area(); } |