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authorJon Doron <arilou@gmail.com>2020-05-29 16:45:40 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2020-06-01 04:26:11 -0400
commitf97f5a56f5977311f3833056a73cdbb0ee56cb1e (patch)
tree5e25d905951ceb38ac155d5779c1cefece494e9e /arch
parent22ad0026d0978d4211eb07a2be77f49fb40d86eb (diff)
x86/kvm/hyper-v: Add support for synthetic debugger interface
Add support for Hyper-V synthetic debugger (syndbg) interface. The syndbg interface is using MSRs to emulate a way to send/recv packets data. The debug transport dll (kdvm/kdnet) will identify if Hyper-V is enabled and if it supports the synthetic debugger interface it will attempt to use it, instead of trying to initialize a network adapter. Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Jon Doron <arilou@gmail.com> Message-Id: <20200529134543.1127440-4-arilou@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/kvm_host.h13
-rw-r--r--arch/x86/kvm/hyperv.c158
-rw-r--r--arch/x86/kvm/hyperv.h5
-rw-r--r--arch/x86/kvm/trace.h51
-rw-r--r--arch/x86/kvm/x86.c8
5 files changed, 232 insertions, 3 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b878fcd164ce..58337a25396a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -863,6 +863,18 @@ struct kvm_apic_map {
struct kvm_lapic *phys_map[];
};
+/* Hyper-V synthetic debugger (SynDbg)*/
+struct kvm_hv_syndbg {
+ struct {
+ u64 control;
+ u64 status;
+ u64 send_page;
+ u64 recv_page;
+ u64 pending_page;
+ } control;
+ u64 options;
+};
+
/* Hyper-V emulation context */
struct kvm_hv {
struct mutex hv_lock;
@@ -886,6 +898,7 @@ struct kvm_hv {
atomic_t num_mismatched_vp_indexes;
struct hv_partition_assist_pg *hv_pa_pg;
+ struct kvm_hv_syndbg hv_syndbg;
};
enum kvm_irqchip_mode {
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index f9d3b919823c..c21f99357ad5 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -21,6 +21,7 @@
#include "x86.h"
#include "lapic.h"
#include "ioapic.h"
+#include "cpuid.h"
#include "hyperv.h"
#include <linux/cpu.h>
@@ -266,6 +267,123 @@ static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
return ret;
}
+static bool kvm_hv_is_syndbg_enabled(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpuid_entry2 *entry;
+
+ entry = kvm_find_cpuid_entry(vcpu,
+ HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES,
+ 0);
+ if (!entry)
+ return false;
+
+ return entry->eax & HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
+}
+
+static int kvm_hv_syndbg_complete_userspace(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct kvm_hv *hv = &kvm->arch.hyperv;
+
+ if (vcpu->run->hyperv.u.syndbg.msr == HV_X64_MSR_SYNDBG_CONTROL)
+ hv->hv_syndbg.control.status =
+ vcpu->run->hyperv.u.syndbg.status;
+ return 1;
+}
+
+static void syndbg_exit(struct kvm_vcpu *vcpu, u32 msr)
+{
+ struct kvm_hv_syndbg *syndbg = vcpu_to_hv_syndbg(vcpu);
+ struct kvm_vcpu_hv *hv_vcpu = &vcpu->arch.hyperv;
+
+ hv_vcpu->exit.type = KVM_EXIT_HYPERV_SYNDBG;
+ hv_vcpu->exit.u.syndbg.msr = msr;
+ hv_vcpu->exit.u.syndbg.control = syndbg->control.control;
+ hv_vcpu->exit.u.syndbg.send_page = syndbg->control.send_page;
+ hv_vcpu->exit.u.syndbg.recv_page = syndbg->control.recv_page;
+ hv_vcpu->exit.u.syndbg.pending_page = syndbg->control.pending_page;
+ vcpu->arch.complete_userspace_io =
+ kvm_hv_syndbg_complete_userspace;
+
+ kvm_make_request(KVM_REQ_HV_EXIT, vcpu);
+}
+
+static int syndbg_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
+{
+ struct kvm_hv_syndbg *syndbg = vcpu_to_hv_syndbg(vcpu);
+
+ if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
+ return 1;
+
+ trace_kvm_hv_syndbg_set_msr(vcpu->vcpu_id,
+ vcpu_to_hv_vcpu(vcpu)->vp_index, msr, data);
+ switch (msr) {
+ case HV_X64_MSR_SYNDBG_CONTROL:
+ syndbg->control.control = data;
+ if (!host)
+ syndbg_exit(vcpu, msr);
+ break;
+ case HV_X64_MSR_SYNDBG_STATUS:
+ syndbg->control.status = data;
+ break;
+ case HV_X64_MSR_SYNDBG_SEND_BUFFER:
+ syndbg->control.send_page = data;
+ break;
+ case HV_X64_MSR_SYNDBG_RECV_BUFFER:
+ syndbg->control.recv_page = data;
+ break;
+ case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
+ syndbg->control.pending_page = data;
+ if (!host)
+ syndbg_exit(vcpu, msr);
+ break;
+ case HV_X64_MSR_SYNDBG_OPTIONS:
+ syndbg->options = data;
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int syndbg_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
+{
+ struct kvm_hv_syndbg *syndbg = vcpu_to_hv_syndbg(vcpu);
+
+ if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
+ return 1;
+
+ switch (msr) {
+ case HV_X64_MSR_SYNDBG_CONTROL:
+ *pdata = syndbg->control.control;
+ break;
+ case HV_X64_MSR_SYNDBG_STATUS:
+ *pdata = syndbg->control.status;
+ break;
+ case HV_X64_MSR_SYNDBG_SEND_BUFFER:
+ *pdata = syndbg->control.send_page;
+ break;
+ case HV_X64_MSR_SYNDBG_RECV_BUFFER:
+ *pdata = syndbg->control.recv_page;
+ break;
+ case HV_X64_MSR_SYNDBG_PENDING_BUFFER:
+ *pdata = syndbg->control.pending_page;
+ break;
+ case HV_X64_MSR_SYNDBG_OPTIONS:
+ *pdata = syndbg->options;
+ break;
+ default:
+ break;
+ }
+
+ trace_kvm_hv_syndbg_get_msr(vcpu->vcpu_id,
+ vcpu_to_hv_vcpu(vcpu)->vp_index, msr,
+ *pdata);
+
+ return 0;
+}
+
static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata,
bool host)
{
@@ -800,6 +918,8 @@ static bool kvm_hv_msr_partition_wide(u32 msr)
case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
case HV_X64_MSR_TSC_EMULATION_CONTROL:
case HV_X64_MSR_TSC_EMULATION_STATUS:
+ case HV_X64_MSR_SYNDBG_OPTIONS:
+ case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
r = true;
break;
}
@@ -1061,6 +1181,9 @@ static int kvm_hv_set_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data,
if (!host)
return 1;
break;
+ case HV_X64_MSR_SYNDBG_OPTIONS:
+ case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
+ return syndbg_set_msr(vcpu, msr, data, host);
default:
vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
msr, data);
@@ -1190,7 +1313,8 @@ static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
return 0;
}
-static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
+static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata,
+ bool host)
{
u64 data = 0;
struct kvm *kvm = vcpu->kvm;
@@ -1227,6 +1351,9 @@ static int kvm_hv_get_msr_pw(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
case HV_X64_MSR_TSC_EMULATION_STATUS:
data = hv->hv_tsc_emulation_status;
break;
+ case HV_X64_MSR_SYNDBG_OPTIONS:
+ case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
+ return syndbg_get_msr(vcpu, msr, pdata, host);
default:
vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
return 1;
@@ -1316,7 +1443,7 @@ int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
int r;
mutex_lock(&vcpu->kvm->arch.hyperv.hv_lock);
- r = kvm_hv_get_msr_pw(vcpu, msr, pdata);
+ r = kvm_hv_get_msr_pw(vcpu, msr, pdata, host);
mutex_unlock(&vcpu->kvm->arch.hyperv.hv_lock);
return r;
} else
@@ -1795,6 +1922,9 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
{ .function = HYPERV_CPUID_FEATURES },
{ .function = HYPERV_CPUID_ENLIGHTMENT_INFO },
{ .function = HYPERV_CPUID_IMPLEMENT_LIMITS },
+ { .function = HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS },
+ { .function = HYPERV_CPUID_SYNDBG_INTERFACE },
+ { .function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES },
{ .function = HYPERV_CPUID_NESTED_FEATURES },
};
int i, nent = ARRAY_SIZE(cpuid_entries);
@@ -1820,7 +1950,7 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
case HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS:
memcpy(signature, "Linux KVM Hv", 12);
- ent->eax = HYPERV_CPUID_NESTED_FEATURES;
+ ent->eax = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES;
ent->ebx = signature[0];
ent->ecx = signature[1];
ent->edx = signature[2];
@@ -1859,6 +1989,10 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
+ ent->ebx |= HV_X64_DEBUGGING;
+ ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE;
+ ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
+
/*
* Direct Synthetic timers only make sense with in-kernel
* LAPIC
@@ -1902,6 +2036,24 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
break;
+ case HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS:
+ memcpy(signature, "Linux KVM Hv", 12);
+
+ ent->eax = 0;
+ ent->ebx = signature[0];
+ ent->ecx = signature[1];
+ ent->edx = signature[2];
+ break;
+
+ case HYPERV_CPUID_SYNDBG_INTERFACE:
+ memcpy(signature, "VS#1\0\0\0\0\0\0\0\0", 12);
+ ent->eax = signature[0];
+ break;
+
+ case HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES:
+ ent->eax |= HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING;
+ break;
+
default:
break;
}
diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h
index 7f50ff0bad07..e68c6c2e9649 100644
--- a/arch/x86/kvm/hyperv.h
+++ b/arch/x86/kvm/hyperv.h
@@ -73,6 +73,11 @@ static inline struct kvm_vcpu *synic_to_vcpu(struct kvm_vcpu_hv_synic *synic)
return hv_vcpu_to_vcpu(container_of(synic, struct kvm_vcpu_hv, synic));
}
+static inline struct kvm_hv_syndbg *vcpu_to_hv_syndbg(struct kvm_vcpu *vcpu)
+{
+ return &vcpu->kvm->arch.hyperv.hv_syndbg;
+}
+
int kvm_hv_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host);
int kvm_hv_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host);
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index 54a10c98d746..b66432b015d2 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -1541,6 +1541,57 @@ TRACE_EVENT(kvm_nested_vmenter_failed,
__print_symbolic(__entry->err, VMX_VMENTER_INSTRUCTION_ERRORS))
);
+/*
+ * Tracepoint for syndbg_set_msr.
+ */
+TRACE_EVENT(kvm_hv_syndbg_set_msr,
+ TP_PROTO(int vcpu_id, u32 vp_index, u32 msr, u64 data),
+ TP_ARGS(vcpu_id, vp_index, msr, data),
+
+ TP_STRUCT__entry(
+ __field(int, vcpu_id)
+ __field(u32, vp_index)
+ __field(u32, msr)
+ __field(u64, data)
+ ),
+
+ TP_fast_assign(
+ __entry->vcpu_id = vcpu_id;
+ __entry->vp_index = vp_index;
+ __entry->msr = msr;
+ __entry->data = data;
+ ),
+
+ TP_printk("vcpu_id %d vp_index %u msr 0x%x data 0x%llx",
+ __entry->vcpu_id, __entry->vp_index, __entry->msr,
+ __entry->data)
+);
+
+/*
+ * Tracepoint for syndbg_get_msr.
+ */
+TRACE_EVENT(kvm_hv_syndbg_get_msr,
+ TP_PROTO(int vcpu_id, u32 vp_index, u32 msr, u64 data),
+ TP_ARGS(vcpu_id, vp_index, msr, data),
+
+ TP_STRUCT__entry(
+ __field(int, vcpu_id)
+ __field(u32, vp_index)
+ __field(u32, msr)
+ __field(u64, data)
+ ),
+
+ TP_fast_assign(
+ __entry->vcpu_id = vcpu_id;
+ __entry->vp_index = vp_index;
+ __entry->msr = msr;
+ __entry->data = data;
+ ),
+
+ TP_printk("vcpu_id %d vp_index %u msr 0x%x data 0x%llx",
+ __entry->vcpu_id, __entry->vp_index, __entry->msr,
+ __entry->data)
+);
#endif /* _TRACE_KVM_H */
#undef TRACE_INCLUDE_PATH
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ca8a57312291..9e41b5135340 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1246,6 +1246,10 @@ static const u32 emulated_msrs_all[] = {
HV_X64_MSR_VP_ASSIST_PAGE,
HV_X64_MSR_REENLIGHTENMENT_CONTROL, HV_X64_MSR_TSC_EMULATION_CONTROL,
HV_X64_MSR_TSC_EMULATION_STATUS,
+ HV_X64_MSR_SYNDBG_OPTIONS,
+ HV_X64_MSR_SYNDBG_CONTROL, HV_X64_MSR_SYNDBG_STATUS,
+ HV_X64_MSR_SYNDBG_SEND_BUFFER, HV_X64_MSR_SYNDBG_RECV_BUFFER,
+ HV_X64_MSR_SYNDBG_PENDING_BUFFER,
MSR_KVM_ASYNC_PF_EN, MSR_KVM_STEAL_TIME,
MSR_KVM_PV_EOI_EN, MSR_KVM_ASYNC_PF_INT, MSR_KVM_ASYNC_PF_ACK,
@@ -3011,6 +3015,8 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
*/
break;
case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
+ case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
+ case HV_X64_MSR_SYNDBG_OPTIONS:
case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
case HV_X64_MSR_CRASH_CTL:
case HV_X64_MSR_STIMER0_CONFIG ... HV_X64_MSR_STIMER3_COUNT:
@@ -3272,6 +3278,8 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
msr_info->data = 0x20000000;
break;
case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
+ case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
+ case HV_X64_MSR_SYNDBG_OPTIONS:
case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
case HV_X64_MSR_CRASH_CTL:
case HV_X64_MSR_STIMER0_CONFIG ... HV_X64_MSR_STIMER3_COUNT: