From 55cd8e5a4edb8e235163ffe8264b9aaa8d7c050f Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Sun, 17 Jan 2010 15:51:22 +0200 Subject: [PATCH] KVM: Implement bare minimum of HYPER-V MSRs Minimum HYPER-V implementation should have GUEST_OS_ID, HYPERCALL and VP_INDEX MSRs. [avi: fix build on i386] Signed-off-by: Gleb Natapov Signed-off-by: Vadim Rozenfeld Signed-off-by: Avi Kivity --- arch/x86/include/asm/kvm_host.h | 4 + arch/x86/include/asm/kvm_para.h | 1 + arch/x86/kvm/trace.h | 32 +++++++ arch/x86/kvm/x86.c | 193 +++++++++++++++++++++++++++++++++++++++- include/linux/kvm.h | 1 + 5 files changed, 230 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 93bee7a..67d19e4 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -413,6 +413,10 @@ struct kvm_arch { s64 kvmclock_offset; struct kvm_xen_hvm_config xen_hvm_config; + + /* fields used by HYPER-V emulation */ + u64 hv_guest_os_id; + u64 hv_hypercall; }; struct kvm_vm_stat { diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index c584076..ffae142 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -2,6 +2,7 @@ #define _ASM_X86_KVM_PARA_H #include +#include /* This CPUID returns the signature 'KVMKVMKVM' in ebx, ecx, and edx. It * should be used to determine that a VM is running under KVM. diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h index 816e044..1cb3d0e 100644 --- a/arch/x86/kvm/trace.h +++ b/arch/x86/kvm/trace.h @@ -56,6 +56,38 @@ TRACE_EVENT(kvm_hypercall, ); /* + * Tracepoint for hypercall. + */ +TRACE_EVENT(kvm_hv_hypercall, + TP_PROTO(__u16 code, bool fast, __u16 rep_cnt, __u16 rep_idx, + __u64 ingpa, __u64 outgpa), + TP_ARGS(code, fast, rep_cnt, rep_idx, ingpa, outgpa), + + TP_STRUCT__entry( + __field( __u16, code ) + __field( bool, fast ) + __field( __u16, rep_cnt ) + __field( __u16, rep_idx ) + __field( __u64, ingpa ) + __field( __u64, outgpa ) + ), + + TP_fast_assign( + __entry->code = code; + __entry->fast = fast; + __entry->rep_cnt = rep_cnt; + __entry->rep_idx = rep_idx; + __entry->ingpa = ingpa; + __entry->outgpa = outgpa; + ), + + TP_printk("code 0x%x %s cnt 0x%x idx 0x%x in 0x%llx out 0x%llx", + __entry->code, __entry->fast ? "fast" : "slow", + __entry->rep_cnt, __entry->rep_idx, __entry->ingpa, + __entry->outgpa) +); + +/* * Tracepoint for PIO. */ TRACE_EVENT(kvm_pio, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 1ad34d1..480137d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -622,9 +622,10 @@ static inline u32 bit(int bitno) * kvm-specific. Those are put in the beginning of the list. */ -#define KVM_SAVE_MSRS_BEGIN 2 +#define KVM_SAVE_MSRS_BEGIN 4 static u32 msrs_to_save[] = { MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK, + HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL, MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP, MSR_K6_STAR, #ifdef CONFIG_X86_64 @@ -1004,6 +1005,74 @@ out: return r; } +static bool kvm_hv_hypercall_enabled(struct kvm *kvm) +{ + return kvm->arch.hv_hypercall & HV_X64_MSR_HYPERCALL_ENABLE; +} + +static bool kvm_hv_msr_partition_wide(u32 msr) +{ + bool r = false; + switch (msr) { + case HV_X64_MSR_GUEST_OS_ID: + case HV_X64_MSR_HYPERCALL: + r = true; + break; + } + + return r; +} + +static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data) +{ + struct kvm *kvm = vcpu->kvm; + + switch (msr) { + case HV_X64_MSR_GUEST_OS_ID: + kvm->arch.hv_guest_os_id = data; + /* setting guest os id to zero disables hypercall page */ + if (!kvm->arch.hv_guest_os_id) + kvm->arch.hv_hypercall &= ~HV_X64_MSR_HYPERCALL_ENABLE; + break; + case HV_X64_MSR_HYPERCALL: { + u64 gfn; + unsigned long addr; + u8 instructions[4]; + + /* if guest os id is not set hypercall should remain disabled */ + if (!kvm->arch.hv_guest_os_id) + break; + if (!(data & HV_X64_MSR_HYPERCALL_ENABLE)) { + kvm->arch.hv_hypercall = data; + break; + } + gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT; + addr = gfn_to_hva(kvm, gfn); + if (kvm_is_error_hva(addr)) + return 1; + kvm_x86_ops->patch_hypercall(vcpu, instructions); + ((unsigned char *)instructions)[3] = 0xc3; /* ret */ + if (copy_to_user((void __user *)addr, instructions, 4)) + return 1; + kvm->arch.hv_hypercall = data; + break; + } + default: + pr_unimpl(vcpu, "HYPER-V unimplemented wrmsr: 0x%x " + "data 0x%llx\n", msr, data); + return 1; + } + return 0; +} + +static int set_msr_hyperv(struct kvm_vcpu *vcpu, u32 msr, u64 data) +{ + pr_unimpl(vcpu, "HYPER-V unimplemented wrmsr: 0x%x data 0x%llx\n", + msr, data); + + return 1; +} + int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data) { switch (msr) { @@ -1118,6 +1187,16 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data) pr_unimpl(vcpu, "unimplemented perfctr wrmsr: " "0x%x data 0x%llx\n", msr, data); break; + case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15: + if (kvm_hv_msr_partition_wide(msr)) { + int r; + mutex_lock(&vcpu->kvm->lock); + r = set_msr_hyperv_pw(vcpu, msr, data); + mutex_unlock(&vcpu->kvm->lock); + return r; + } else + return set_msr_hyperv(vcpu, msr, data); + break; default: if (msr && (msr == vcpu->kvm->arch.xen_hvm_config.msr)) return xen_hvm_config(vcpu, data); @@ -1217,6 +1296,48 @@ static int get_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) return 0; } +static int get_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) +{ + u64 data = 0; + struct kvm *kvm = vcpu->kvm; + + switch (msr) { + case HV_X64_MSR_GUEST_OS_ID: + data = kvm->arch.hv_guest_os_id; + break; + case HV_X64_MSR_HYPERCALL: + data = kvm->arch.hv_hypercall; + break; + default: + pr_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr); + return 1; + } + + *pdata = data; + return 0; +} + +static int get_msr_hyperv(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) +{ + u64 data = 0; + + switch (msr) { + case HV_X64_MSR_VP_INDEX: { + int r; + struct kvm_vcpu *v; + kvm_for_each_vcpu(r, v, vcpu->kvm) + if (v == vcpu) + data = r; + break; + } + default: + pr_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr); + return 1; + } + *pdata = data; + return 0; +} + int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) { u64 data; @@ -1283,6 +1404,16 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) case MSR_IA32_MCG_STATUS: case MSR_IA32_MC0_CTL ... MSR_IA32_MC0_CTL + 4 * KVM_MAX_MCE_BANKS - 1: return get_msr_mce(vcpu, msr, pdata); + case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15: + if (kvm_hv_msr_partition_wide(msr)) { + int r; + mutex_lock(&vcpu->kvm->lock); + r = get_msr_hyperv_pw(vcpu, msr, pdata); + mutex_unlock(&vcpu->kvm->lock); + return r; + } else + return get_msr_hyperv(vcpu, msr, pdata); + break; default: if (!ignore_msrs) { pr_unimpl(vcpu, "unhandled rdmsr: 0x%x\n", msr); @@ -1398,6 +1529,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_XEN_HVM: case KVM_CAP_ADJUST_CLOCK: case KVM_CAP_VCPU_EVENTS: + case KVM_CAP_HYPERV: r = 1; break; case KVM_CAP_COALESCED_MMIO: @@ -3618,11 +3750,70 @@ static inline gpa_t hc_gpa(struct kvm_vcpu *vcpu, unsigned long a0, return a0 | ((gpa_t)a1 << 32); } +int kvm_hv_hypercall(struct kvm_vcpu *vcpu) +{ + u64 param, ingpa, outgpa, ret; + uint16_t code, rep_idx, rep_cnt, res = HV_STATUS_SUCCESS, rep_done = 0; + bool fast, longmode; + int cs_db, cs_l; + + /* + * hypercall generates UD from non zero cpl and real mode + * per HYPER-V spec + */ + if (kvm_x86_ops->get_cpl(vcpu) != 0 || + !kvm_read_cr0_bits(vcpu, X86_CR0_PE)) { + kvm_queue_exception(vcpu, UD_VECTOR); + return 0; + } + + kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l); + longmode = is_long_mode(vcpu) && cs_l == 1; + + if (!longmode) { + param = (kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) | + (kvm_register_read(vcpu, VCPU_REGS_RAX) & 0xffffff); + ingpa = (kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) | + (kvm_register_read(vcpu, VCPU_REGS_RCX) & 0xffffff); + outgpa = (kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) | + (kvm_register_read(vcpu, VCPU_REGS_RSI) & 0xffffff); + } +#ifdef CONFIG_X86_64 + else { + param = kvm_register_read(vcpu, VCPU_REGS_RCX); + ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX); + outgpa = kvm_register_read(vcpu, VCPU_REGS_R8); + } +#endif + + code = param & 0xffff; + fast = (param >> 16) & 0x1; + rep_cnt = (param >> 32) & 0xfff; + rep_idx = (param >> 48) & 0xfff; + + trace_kvm_hv_hypercall(code, fast, rep_cnt, rep_idx, ingpa, outgpa); + + res = HV_STATUS_INVALID_HYPERCALL_CODE; + + ret = res | (((u64)rep_done & 0xfff) << 32); + if (longmode) { + kvm_register_write(vcpu, VCPU_REGS_RAX, ret); + } else { + kvm_register_write(vcpu, VCPU_REGS_RDX, ret >> 32); + kvm_register_write(vcpu, VCPU_REGS_RAX, ret & 0xffffffff); + } + + return 1; +} + int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) { unsigned long nr, a0, a1, a2, a3, ret; int r = 1; + if (kvm_hv_hypercall_enabled(vcpu->kvm)) + return kvm_hv_hypercall(vcpu); + nr = kvm_register_read(vcpu, VCPU_REGS_RAX); a0 = kvm_register_read(vcpu, VCPU_REGS_RBX); a1 = kvm_register_read(vcpu, VCPU_REGS_RCX); diff --git a/include/linux/kvm.h b/include/linux/kvm.h index f2feef6..e227cba 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -497,6 +497,7 @@ struct kvm_ioeventfd { #endif #define KVM_CAP_S390_PSW 42 #define KVM_CAP_PPC_SEGSTATE 43 +#define KVM_CAP_HYPERV 44 #ifdef KVM_CAP_IRQ_ROUTING -- 2.7.4