From: Jon Doron <arilou@xxxxxxxxx> Sent: Friday, March 13, 2020 9:45 PM
>
> On 13/03/2020, Michael Kelley wrote:
> >From: Jon Doron <arilou@xxxxxxxxx> Sent: Friday, March 13, 2020 6:21 AM
> >>
> >> Hyper-V synthetic debugger has two modes, one that uses MSRs and
> >> the other that use Hypercalls.
> >>
> >> Add all the required definitions to both types of synthetic debugger
> >> interface.
> >>
> >> Some of the required new CPUIDs and MSRs are not documented in the TLFS
> >> so they are in hyperv.h instead.
> >>
> >> Signed-off-by: Jon Doron <arilou@xxxxxxxxx>
> >> ---
> >> arch/x86/include/asm/hyperv-tlfs.h | 6 ++++++
> >> arch/x86/kvm/hyperv.h | 22 ++++++++++++++++++++++
> >> 2 files changed, 28 insertions(+)
> >>
> >> diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
> >> index 92abc1e42bfc..671ce2a39d4b 100644
> >> --- a/arch/x86/include/asm/hyperv-tlfs.h
> >> +++ b/arch/x86/include/asm/hyperv-tlfs.h
> >> @@ -131,6 +131,8 @@
> >> #define HV_FEATURE_FREQUENCY_MSRS_AVAILABLE BIT(8)
> >> /* Crash MSR available */
> >> #define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE BIT(10)
> >> +/* Support for debug MSRs available */
> >> +#define HV_FEATURE_DEBUG_MSRS_AVAILABLE BIT(11)
> >> /* stimer Direct Mode is available */
> >> #define HV_STIMER_DIRECT_MODE_AVAILABLE BIT(19)
> >>
> >> @@ -376,6 +378,9 @@ struct hv_tsc_emulation_status {
> >> #define HVCALL_SEND_IPI_EX 0x0015
> >> #define HVCALL_POST_MESSAGE 0x005c
> >> #define HVCALL_SIGNAL_EVENT 0x005d
> >> +#define HVCALL_POST_DEBUG_DATA 0x0069
> >> +#define HVCALL_RETRIEVE_DEBUG_DATA 0x006a
> >> +#define HVCALL_RESET_DEBUG_SESSION 0x006b
> >> #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE 0x00af
> >> #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST 0x00b0
> >>
> >> @@ -419,6 +424,7 @@ enum HV_GENERIC_SET_FORMAT {
> >> #define HV_STATUS_INVALID_HYPERCALL_INPUT 3
> >> #define HV_STATUS_INVALID_ALIGNMENT 4
> >> #define HV_STATUS_INVALID_PARAMETER 5
> >> +#define HV_STATUS_OPERATION_DENIED 8
> >> #define HV_STATUS_INSUFFICIENT_MEMORY 11
> >> #define HV_STATUS_INVALID_PORT_ID 17
> >> #define HV_STATUS_INVALID_CONNECTION_ID 18
> >> diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h
> >> index 757cb578101c..56bc3416b62f 100644
> >> --- a/arch/x86/kvm/hyperv.h
> >> +++ b/arch/x86/kvm/hyperv.h
> >> @@ -23,6 +23,28 @@
> >>
> >> #include <linux/kvm_host.h>
> >>
> >> +/* These defines are required by KDNet and they are not part of Hyper-V TLFS */
> >
> >I'm looking for a bit more info in the comment so that it's clear that the
> >synthetic debugger functionality is not committed to be available going
> >forward. Perhaps something along the lines of:
> >
> >/* The #defines related to the synthetic debugger are required by KDNet, but
> > * they are not documented in the Hyper-V TLFS because the synthetic debugger
> > * functionality has been deprecated and is subject to removal in future versions
> > * of Windows.
> > */
> >
> >But with that additional comment text,
> >
> >Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
> >
>
> Sure thing, but one quick question I have noticed that in the 6.0 TLFS
> the bit indicating the DEBUG_MSRS are available is still documented is
> that intentional or a juss a miss?
>From the side conversation I had with the Hyper-V people, I think
this is just a miss. They took out the MSR definitions, but forgot to
take out the flag indicating the presence of the MSRs. As I think I
mentioned in an earlier email, there will be future updates to the
TLFS, and I've put this topic on my list of things to make sure get
cleaned up.
Michael
>
> Cheers,
> -- Jon.
>
> >> +#define HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS 0x40000080
> >> +#define HYPERV_CPUID_SYNDBG_INTERFACE 0x40000081
> >> +#define HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES 0x40000082
> >> +
> >> +/*
> >> + * Hyper-V synthetic debugger platform capabilities
> >> + * These are HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES.EAX bits.
> >> + */
> >> +#define HV_X64_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING BIT(1)
> >> +
> >> +/* Hyper-V Synthetic debug options MSR */
> >> +#define HV_X64_MSR_SYNDBG_CONTROL 0x400000F1
> >> +#define HV_X64_MSR_SYNDBG_STATUS 0x400000F2
> >> +#define HV_X64_MSR_SYNDBG_SEND_BUFFER 0x400000F3
> >> +#define HV_X64_MSR_SYNDBG_RECV_BUFFER 0x400000F4
> >> +#define HV_X64_MSR_SYNDBG_PENDING_BUFFER 0x400000F5
> >> +#define HV_X64_MSR_SYNDBG_OPTIONS 0x400000FF
> >> +
> >> +/* Hyper-V HV_X64_MSR_SYNDBG_OPTIONS bits */
> >> +#define HV_X64_SYNDBG_OPTION_USE_HCALLS BIT(2)
> >> +
> >> static inline struct kvm_vcpu_hv *vcpu_to_hv_vcpu(struct kvm_vcpu *vcpu)
> >> {
> >> return &vcpu->arch.hyperv;
> >> --
> >> 2.24.1
> >
