From: Jon Doron <arilou@gmail.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: kvm@vger.kernel.org, linux-hyperv@vger.kernel.org
Subject: Re: [PATCH v3 3/5] x86/kvm/hyper-v: Add support for synthetic debugger capability
Date: Mon, 9 Mar 2020 20:20:47 +0200 [thread overview]
Message-ID: <20200309182047.GB3755153@jondnuc> (raw)
In-Reply-To: <87h7yxcxiu.fsf@vitty.brq.redhat.com>
On 09/03/2020, Vitaly Kuznetsov wrote:
>Jon Doron <arilou@gmail.com> writes:
>
>> 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.
>>
>> Signed-off-by: Jon Doron <arilou@gmail.com>
>> ---
>> arch/x86/include/asm/kvm_host.h | 13 ++++
>> arch/x86/kvm/hyperv.c | 134 +++++++++++++++++++++++++++++++-
>> arch/x86/kvm/hyperv.h | 5 ++
>> arch/x86/kvm/trace.h | 48 ++++++++++++
>> arch/x86/kvm/x86.c | 9 +++
>> include/uapi/linux/kvm.h | 10 +++
>> 6 files changed, 218 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
>> index 98959e8cd448..f8e58e8866bb 100644
>> --- a/arch/x86/include/asm/kvm_host.h
>> +++ b/arch/x86/include/asm/kvm_host.h
>> @@ -854,6 +854,18 @@ 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;
>> @@ -877,6 +889,7 @@ 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 a86fda7a1d03..554e78f961bc 100644
>> --- a/arch/x86/kvm/hyperv.c
>> +++ b/arch/x86/kvm/hyperv.c
>> @@ -266,6 +266,106 @@ static int synic_set_msr(struct kvm_vcpu_hv_synic *synic,
>> return ret;
>> }
>>
>> +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)
>> +{
>> + struct kvm_hv_syndbg *syndbg = vcpu_to_hv_syndbg(vcpu);
>> + int ret;
>> +
>> + trace_kvm_hv_syndbg_set_msr(vcpu->vcpu_id,
>> + vcpu_to_hv_vcpu(vcpu)->vp_index, msr, data);
>> + ret = 0;
>> + switch (msr) {
>> + case HV_X64_MSR_SYNDBG_CONTROL:
>> + syndbg->control.control = data;
>> + 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;
>> + syndbg_exit(vcpu, msr);
>> + break;
>> + case HV_X64_MSR_SYNDBG_OPTIONS:
>> + syndbg->options = data;
>> + break;
>> + default:
>> + ret = 1;
>> + break;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static int syndbg_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
>> +{
>> + struct kvm_hv_syndbg *syndbg = vcpu_to_hv_syndbg(vcpu);
>> + int ret;
>> +
>> + trace_kvm_hv_syndbg_get_msr(vcpu->vcpu_id,
>> + vcpu_to_hv_vcpu(vcpu)->vp_index, msr);
>> + ret = 0;
>> + 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:
>> + ret = 1;
>> + break;
>> + }
>> +
>
>Nitpick: I would've moved trace_kvm_hv_syndbg_get_msr() here so we can
>actually see the value (*pdata) which was read. kvm_hv_syndbg_get_msr()
>tracepoint will now look exactly as kvm_hv_syndbg_set_msr().
>
>
Done.
>> + return ret;
>> +}
>> +
>> static int synic_get_msr(struct kvm_vcpu_hv_synic *synic, u32 msr, u64 *pdata,
>> bool host)
>> {
>> @@ -800,6 +900,8 @@ 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 +1163,9 @@ 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);
>> default:
>> vcpu_unimpl(vcpu, "Hyper-V unhandled wrmsr: 0x%x data 0x%llx\n",
>> msr, data);
>> @@ -1227,6 +1332,9 @@ 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);
>> default:
>> vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
>> return 1;
>> @@ -1797,6 +1905,9 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
>> { .function = HYPERV_CPUID_ENLIGHTMENT_INFO },
>> { .function = HYPERV_CPUID_IMPLEMENT_LIMITS },
>> { .function = HYPERV_CPUID_NESTED_FEATURES },
>> + { .function = HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS },
>> + { .function = HYPERV_CPUID_SYNDBG_INTERFACE },
>> + { .function = HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES },
>> };
>> int i, nent = ARRAY_SIZE(cpuid_entries);
>>
>> @@ -1821,7 +1932,7 @@ 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];
>> @@ -1856,9 +1967,12 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
>>
>> ent->ebx |= HV_X64_POST_MESSAGES;
>> ent->ebx |= HV_X64_SIGNAL_EVENTS;
>> + ent->ebx |= HV_X64_DEBUGGING;
>>
>> ent->edx |= HV_FEATURE_FREQUENCY_MSRS_AVAILABLE;
>> ent->edx |= HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
>> + ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE;
>> + ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
>>
>> /*
>> * Direct Synthetic timers only make sense with in-kernel
>> @@ -1903,6 +2017,24 @@ 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 757cb578101c..6a86151fac53 100644
>> --- a/arch/x86/kvm/hyperv.h
>> +++ b/arch/x86/kvm/hyperv.h
>> @@ -46,6 +46,11 @@ 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 f194dd058470..97f4edea0e71 100644
>> --- a/arch/x86/kvm/trace.h
>> +++ b/arch/x86/kvm/trace.h
>> @@ -1515,6 +1515,54 @@ 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),
>> + TP_ARGS(vcpu_id, vp_index, msr),
>> +
>> + TP_STRUCT__entry(
>> + __field(int, vcpu_id)
>> + __field(u32, vp_index)
>> + __field(u32, msr)
>> + ),
>> +
>> + TP_fast_assign(
>> + __entry->vcpu_id = vcpu_id;
>> + __entry->vp_index = vp_index;
>> + __entry->msr = msr;
>> + ),
>> +
>> + TP_printk("vcpu_id %d vp_index %u msr 0x%x",
>> + __entry->vcpu_id, __entry->vp_index, __entry->msr)
>> +);
>> #endif /* _TRACE_KVM_H */
>>
>> #undef TRACE_INCLUDE_PATH
>> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
>> index 5de200663f51..619c24bac79e 100644
>> --- a/arch/x86/kvm/x86.c
>> +++ b/arch/x86/kvm/x86.c
>> @@ -1214,6 +1214,10 @@ 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,
>> @@ -2906,6 +2910,8 @@ 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:
>> @@ -3151,6 +3157,8 @@ 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:
>> @@ -3323,6 +3331,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>> case KVM_CAP_HYPERV_TLBFLUSH:
>> case KVM_CAP_HYPERV_SEND_IPI:
>> case KVM_CAP_HYPERV_CPUID:
>> + case KVM_CAP_HYPERV_DEBUGGING:
>> case KVM_CAP_PCI_SEGMENT:
>> case KVM_CAP_DEBUGREGS:
>> case KVM_CAP_X86_ROBUST_SINGLESTEP:
>> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
>> index 24b7c48ccc6f..97a208728b3d 100644
>> --- a/include/uapi/linux/kvm.h
>> +++ b/include/uapi/linux/kvm.h
>> @@ -188,6 +188,7 @@ struct kvm_s390_cmma_log {
>> struct kvm_hyperv_exit {
>> #define KVM_EXIT_HYPERV_SYNIC 1
>> #define KVM_EXIT_HYPERV_HCALL 2
>> +#define KVM_EXIT_HYPERV_SYNDBG 3
>> __u32 type;
>> union {
>> struct {
>> @@ -202,6 +203,14 @@ struct kvm_hyperv_exit {
>> __u64 result;
>> __u64 params[2];
>> } hcall;
>> + struct {
>> + __u32 msr;
>> + __u64 control;
>> + __u64 status;
>> + __u64 send_page;
>> + __u64 recv_page;
>> + __u64 pending_page;
>> + } syndbg;
>> } u;
>> };
>>
>> @@ -1011,6 +1020,7 @@ struct kvm_ppc_resize_hpt {
>> #define KVM_CAP_ARM_NISV_TO_USER 177
>> #define KVM_CAP_ARM_INJECT_EXT_DABT 178
>> #define KVM_CAP_S390_VCPU_RESETS 179
>> +#define KVM_CAP_HYPERV_DEBUGGING 180
>>
>> #ifdef KVM_CAP_IRQ_ROUTING
>
>--
>Vitaly
>
next prev parent reply other threads:[~2020-03-09 18:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-06 16:39 [PATCH v3 0/5] x86/kvm/hyper-v: add support for synthetic debugger Jon Doron
2020-03-06 16:39 ` [PATCH v3 1/5] x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit Jon Doron
2020-03-09 16:13 ` Vitaly Kuznetsov
2020-03-09 18:11 ` Jon Doron
2020-03-06 16:39 ` [PATCH v3 2/5] x86/hyper-v: Add synthetic debugger definitions Jon Doron
2020-03-06 16:39 ` [PATCH v3 3/5] x86/kvm/hyper-v: Add support for synthetic debugger capability Jon Doron
2020-03-09 16:18 ` Vitaly Kuznetsov
2020-03-09 18:20 ` Jon Doron [this message]
2020-03-06 16:39 ` [PATCH v3 4/5] x86/kvm/hyper-v: enable hypercalls regardless of hypercall page Jon Doron
2020-03-06 16:39 ` [PATCH v3 5/5] x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls Jon Doron
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