[RFC,V5,03/15] x86/hyperv: Set Virtual Trust Level in VMBus init message
Commit Message
From: Tianyu Lan <tiala@microsoft.com>
sev-snp guest provides vtl(Virtual Trust Level) and
get it from hyperv hvcall via HVCALL_GET_VP_REGISTERS.
Set target vtl in the VMBus init message.
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
---
Change since RFC v4:
* Use struct_size to calculate array size.
* Fix some coding style
Change since RFC v3:
* Use the standard helper functions to check hypercall result
* Fix coding style
Change since RFC v2:
* Rename get_current_vtl() to get_vtl()
* Fix some coding style issues
---
arch/x86/hyperv/hv_init.c | 36 ++++++++++++++++++++++++++++++
arch/x86/include/asm/hyperv-tlfs.h | 7 ++++++
drivers/hv/connection.c | 1 +
include/asm-generic/mshyperv.h | 1 +
include/linux/hyperv.h | 4 ++--
5 files changed, 47 insertions(+), 2 deletions(-)
Comments
On Mon, 1 May 2023 04:57:13 -0400
Tianyu Lan <ltykernel@gmail.com> wrote:
> From: Tianyu Lan <tiala@microsoft.com>
>
> sev-snp guest provides vtl(Virtual Trust Level) and
> get it from hyperv hvcall via HVCALL_GET_VP_REGISTERS.
> Set target vtl in the VMBus init message.
>
> Signed-off-by: Tianyu Lan <tiala@microsoft.com>
> ---
> Change since RFC v4:
> * Use struct_size to calculate array size.
> * Fix some coding style
>
> Change since RFC v3:
> * Use the standard helper functions to check hypercall result
> * Fix coding style
>
> Change since RFC v2:
> * Rename get_current_vtl() to get_vtl()
> * Fix some coding style issues
> ---
> arch/x86/hyperv/hv_init.c | 36 ++++++++++++++++++++++++++++++
> arch/x86/include/asm/hyperv-tlfs.h | 7 ++++++
> drivers/hv/connection.c | 1 +
> include/asm-generic/mshyperv.h | 1 +
> include/linux/hyperv.h | 4 ++--
> 5 files changed, 47 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index 9f3e2d71d015..331b855314b7 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -384,6 +384,40 @@ static void __init hv_get_partition_id(void)
> local_irq_restore(flags);
> }
>
> +static u8 __init get_vtl(void)
> +{
> + u64 control = HV_HYPERCALL_REP_COMP_1 | HVCALL_GET_VP_REGISTERS;
> + struct hv_get_vp_registers_input *input;
> + struct hv_get_vp_registers_output *output;
> + u64 vtl = 0;
> + u64 ret;
> + unsigned long flags;
> +
> + local_irq_save(flags);
> + input = *this_cpu_ptr(hyperv_pcpu_input_arg);
> + output = (struct hv_get_vp_registers_output *)input;
===
> + if (!input) {
> + local_irq_restore(flags);
> + goto done;
> + }
> +
===
Is this really necessary?
drivers/hv/hv_common.c:
hyperv_pcpu_input_arg = alloc_percpu(void *);
BUG_ON(!hyperv_pcpu_input_arg);
> + memset(input, 0, struct_size(input, element, 1));
> + input->header.partitionid = HV_PARTITION_ID_SELF;
> + input->header.vpindex = HV_VP_INDEX_SELF;
> + input->header.inputvtl = 0;
> + input->element[0].name0 = HV_X64_REGISTER_VSM_VP_STATUS;
> +
> + ret = hv_do_hypercall(control, input, output);
> + if (hv_result_success(ret))
> + vtl = output->as64.low & HV_X64_VTL_MASK;
> + else
> + pr_err("Hyper-V: failed to get VTL! %lld", ret);
> + local_irq_restore(flags);
> +
> +done:
> + return vtl;
> +}
> +
> /*
> * This function is to be invoked early in the boot sequence after the
> * hypervisor has been detected.
> @@ -512,6 +546,8 @@ void __init hyperv_init(void)
> /* Query the VMs extended capability once, so that it can be cached. */
> hv_query_ext_cap(0);
>
> + /* Find the VTL */
> + ms_hyperv.vtl = get_vtl();
> return;
>
> clean_guest_os_id:
> diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
> index cea95dcd27c2..4bf0b315b0ce 100644
> --- a/arch/x86/include/asm/hyperv-tlfs.h
> +++ b/arch/x86/include/asm/hyperv-tlfs.h
> @@ -301,6 +301,13 @@ enum hv_isolation_type {
> #define HV_X64_MSR_TIME_REF_COUNT HV_REGISTER_TIME_REF_COUNT
> #define HV_X64_MSR_REFERENCE_TSC HV_REGISTER_REFERENCE_TSC
>
> +/*
> + * Registers are only accessible via HVCALL_GET_VP_REGISTERS hvcall and
> + * there is not associated MSR address.
> + */
> +#define HV_X64_REGISTER_VSM_VP_STATUS 0x000D0003
> +#define HV_X64_VTL_MASK GENMASK(3, 0)
> +
> /* Hyper-V memory host visibility */
> enum hv_mem_host_visibility {
> VMBUS_PAGE_NOT_VISIBLE = 0,
> diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
> index 5978e9dbc286..02b54f85dc60 100644
> --- a/drivers/hv/connection.c
> +++ b/drivers/hv/connection.c
> @@ -98,6 +98,7 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
> */
> if (version >= VERSION_WIN10_V5) {
> msg->msg_sint = VMBUS_MESSAGE_SINT;
> + msg->msg_vtl = ms_hyperv.vtl;
> vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID_4;
> } else {
> msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index 402a8c1c202d..3052130ba4ef 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -48,6 +48,7 @@ struct ms_hyperv_info {
> };
> };
> u64 shared_gpa_boundary;
> + u8 vtl;
> };
> extern struct ms_hyperv_info ms_hyperv;
> extern bool hv_nested;
> diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
> index bfbc37ce223b..1f2bfec4abde 100644
> --- a/include/linux/hyperv.h
> +++ b/include/linux/hyperv.h
> @@ -665,8 +665,8 @@ struct vmbus_channel_initiate_contact {
> u64 interrupt_page;
> struct {
> u8 msg_sint;
> - u8 padding1[3];
> - u32 padding2;
> + u8 msg_vtl;
> + u8 reserved[6];
> };
> };
> u64 monitor_page1;
On 5/2/2023 12:30 PM, Zhi Wang wrote:
> On Mon, 1 May 2023 04:57:13 -0400
> Tianyu Lan <ltykernel@gmail.com> wrote:
>
>> From: Tianyu Lan <tiala@microsoft.com>
>>
>> sev-snp guest provides vtl(Virtual Trust Level) and
>> get it from hyperv hvcall via HVCALL_GET_VP_REGISTERS.
>> Set target vtl in the VMBus init message.
>>
>> Signed-off-by: Tianyu Lan <tiala@microsoft.com>
>> ---
>> Change since RFC v4:
>> * Use struct_size to calculate array size.
>> * Fix some coding style
>>
>> Change since RFC v3:
>> * Use the standard helper functions to check hypercall result
>> * Fix coding style
>>
>> Change since RFC v2:
>> * Rename get_current_vtl() to get_vtl()
>> * Fix some coding style issues
>> ---
>> arch/x86/hyperv/hv_init.c | 36 ++++++++++++++++++++++++++++++
>> arch/x86/include/asm/hyperv-tlfs.h | 7 ++++++
>> drivers/hv/connection.c | 1 +
>> include/asm-generic/mshyperv.h | 1 +
>> include/linux/hyperv.h | 4 ++--
>> 5 files changed, 47 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
>> index 9f3e2d71d015..331b855314b7 100644
>> --- a/arch/x86/hyperv/hv_init.c
>> +++ b/arch/x86/hyperv/hv_init.c
>> @@ -384,6 +384,40 @@ static void __init hv_get_partition_id(void)
>> local_irq_restore(flags);
>> }
>>
>> +static u8 __init get_vtl(void)
>> +{
>> + u64 control = HV_HYPERCALL_REP_COMP_1 | HVCALL_GET_VP_REGISTERS;
>> + struct hv_get_vp_registers_input *input;
>> + struct hv_get_vp_registers_output *output;
>> + u64 vtl = 0;
>> + u64 ret;
>> + unsigned long flags;
>> +
>> + local_irq_save(flags);
>> + input = *this_cpu_ptr(hyperv_pcpu_input_arg);
>> + output = (struct hv_get_vp_registers_output *)input;
>
> ===
>> + if (!input) {
>> + local_irq_restore(flags);
>> + goto done;
>> + }
>> +
> ===
> Is this really necessary?
>
> drivers/hv/hv_common.c:
>
> hyperv_pcpu_input_arg = alloc_percpu(void *);
> BUG_ON(!hyperv_pcpu_input_arg);
>
>
Hi Zhi:
The hyperv_pcpu_input_arg is a point to address of input arg
pages and these pages are allocated in the hv_common_cpu_init(). If
it failed to allocate these pages, the value pointed by
hyperv_pcpu_input_arg will be NULL.
On Thu, 4 May 2023 08:38:46 -0700
Tianyu Lan <ltykernel@gmail.com> wrote:
> On 5/2/2023 12:30 PM, Zhi Wang wrote:
> > On Mon, 1 May 2023 04:57:13 -0400
> > Tianyu Lan <ltykernel@gmail.com> wrote:
> >
> >> From: Tianyu Lan <tiala@microsoft.com>
> >>
> >> sev-snp guest provides vtl(Virtual Trust Level) and
> >> get it from hyperv hvcall via HVCALL_GET_VP_REGISTERS.
> >> Set target vtl in the VMBus init message.
> >>
> >> Signed-off-by: Tianyu Lan <tiala@microsoft.com>
> >> ---
> >> Change since RFC v4:
> >> * Use struct_size to calculate array size.
> >> * Fix some coding style
> >>
> >> Change since RFC v3:
> >> * Use the standard helper functions to check hypercall result
> >> * Fix coding style
> >>
> >> Change since RFC v2:
> >> * Rename get_current_vtl() to get_vtl()
> >> * Fix some coding style issues
> >> ---
> >> arch/x86/hyperv/hv_init.c | 36 ++++++++++++++++++++++++++++++
> >> arch/x86/include/asm/hyperv-tlfs.h | 7 ++++++
> >> drivers/hv/connection.c | 1 +
> >> include/asm-generic/mshyperv.h | 1 +
> >> include/linux/hyperv.h | 4 ++--
> >> 5 files changed, 47 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> >> index 9f3e2d71d015..331b855314b7 100644
> >> --- a/arch/x86/hyperv/hv_init.c
> >> +++ b/arch/x86/hyperv/hv_init.c
> >> @@ -384,6 +384,40 @@ static void __init hv_get_partition_id(void)
> >> local_irq_restore(flags);
> >> }
> >>
> >> +static u8 __init get_vtl(void)
> >> +{
> >> + u64 control = HV_HYPERCALL_REP_COMP_1 | HVCALL_GET_VP_REGISTERS;
> >> + struct hv_get_vp_registers_input *input;
> >> + struct hv_get_vp_registers_output *output;
> >> + u64 vtl = 0;
> >> + u64 ret;
> >> + unsigned long flags;
> >> +
> >> + local_irq_save(flags);
> >> + input = *this_cpu_ptr(hyperv_pcpu_input_arg);
> >> + output = (struct hv_get_vp_registers_output *)input;
> >
> > ===
> >> + if (!input) {
> >> + local_irq_restore(flags);
> >> + goto done;
> >> + }
> >> +
> > ===
> > Is this really necessary?
> >
> > drivers/hv/hv_common.c:
> >
> > hyperv_pcpu_input_arg = alloc_percpu(void *);
> > BUG_ON(!hyperv_pcpu_input_arg);
> >
> >
>
> Hi Zhi:
> The hyperv_pcpu_input_arg is a point to address of input arg
> pages and these pages are allocated in the hv_common_cpu_init(). If
> it failed to allocate these pages, the value pointed by
> hyperv_pcpu_input_arg will be NULL.
>
Sorry, it seems my email editor dropped some text. I was wondering that
if the check above is necessary as there is a BUG_ON() when allocating
hyperv_pcpu_input_arg.
So when coming to get_vtl(), the hyperv_pcpu_input_arg should not be NULL.
(Guarded by the BUG_ON() in the allocation)?
@@ -384,6 +384,40 @@ static void __init hv_get_partition_id(void)
local_irq_restore(flags);
}
+static u8 __init get_vtl(void)
+{
+ u64 control = HV_HYPERCALL_REP_COMP_1 | HVCALL_GET_VP_REGISTERS;
+ struct hv_get_vp_registers_input *input;
+ struct hv_get_vp_registers_output *output;
+ u64 vtl = 0;
+ u64 ret;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ input = *this_cpu_ptr(hyperv_pcpu_input_arg);
+ output = (struct hv_get_vp_registers_output *)input;
+ if (!input) {
+ local_irq_restore(flags);
+ goto done;
+ }
+
+ memset(input, 0, struct_size(input, element, 1));
+ input->header.partitionid = HV_PARTITION_ID_SELF;
+ input->header.vpindex = HV_VP_INDEX_SELF;
+ input->header.inputvtl = 0;
+ input->element[0].name0 = HV_X64_REGISTER_VSM_VP_STATUS;
+
+ ret = hv_do_hypercall(control, input, output);
+ if (hv_result_success(ret))
+ vtl = output->as64.low & HV_X64_VTL_MASK;
+ else
+ pr_err("Hyper-V: failed to get VTL! %lld", ret);
+ local_irq_restore(flags);
+
+done:
+ return vtl;
+}
+
/*
* This function is to be invoked early in the boot sequence after the
* hypervisor has been detected.
@@ -512,6 +546,8 @@ void __init hyperv_init(void)
/* Query the VMs extended capability once, so that it can be cached. */
hv_query_ext_cap(0);
+ /* Find the VTL */
+ ms_hyperv.vtl = get_vtl();
return;
clean_guest_os_id:
@@ -301,6 +301,13 @@ enum hv_isolation_type {
#define HV_X64_MSR_TIME_REF_COUNT HV_REGISTER_TIME_REF_COUNT
#define HV_X64_MSR_REFERENCE_TSC HV_REGISTER_REFERENCE_TSC
+/*
+ * Registers are only accessible via HVCALL_GET_VP_REGISTERS hvcall and
+ * there is not associated MSR address.
+ */
+#define HV_X64_REGISTER_VSM_VP_STATUS 0x000D0003
+#define HV_X64_VTL_MASK GENMASK(3, 0)
+
/* Hyper-V memory host visibility */
enum hv_mem_host_visibility {
VMBUS_PAGE_NOT_VISIBLE = 0,
@@ -98,6 +98,7 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
*/
if (version >= VERSION_WIN10_V5) {
msg->msg_sint = VMBUS_MESSAGE_SINT;
+ msg->msg_vtl = ms_hyperv.vtl;
vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID_4;
} else {
msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
@@ -48,6 +48,7 @@ struct ms_hyperv_info {
};
};
u64 shared_gpa_boundary;
+ u8 vtl;
};
extern struct ms_hyperv_info ms_hyperv;
extern bool hv_nested;
@@ -665,8 +665,8 @@ struct vmbus_channel_initiate_contact {
u64 interrupt_page;
struct {
u8 msg_sint;
- u8 padding1[3];
- u32 padding2;
+ u8 msg_vtl;
+ u8 reserved[6];
};
};
u64 monitor_page1;