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x86/hyperv: Set Virtual Trust Level in VMBus init message

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SEV-SNP guests on Hyper-V can run at multiple Virtual Trust
Levels (VTL).  During boot, get the VTL at which we're running
using the GET_VP_REGISTERs hypercall, and save the value
for future use.  Then during VMBus initialization, set the VTL
with the saved value as required in the VMBus init message.

Reviewed-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20230818102919.1318039-3-ltykernel@gmail.com
This commit is contained in:
Tianyu Lan 2023-08-18 06:29:12 -04:00 committed by Wei Liu
parent d6e2d65244
commit 8387ce06d7
5 changed files with 45 additions and 2 deletions
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34
arch/x86/hyperv/hv_init.c
View File

@ -378,6 +378,36 @@ 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;
unsigned long flags;
u64 ret;
local_irq_save(flags);
input = *this_cpu_ptr(hyperv_pcpu_input_arg);
output = (struct hv_get_vp_registers_output *)input;
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)) {
ret = output->as64.low & HV_X64_VTL_MASK;
} else {
pr_err("Failed to get VTL(%lld) and set VTL to zero by default.\n", ret);
ret = 0;
}
local_irq_restore(flags);
return ret;
}
/*
* This function is to be invoked early in the boot sequence after the
* hypervisor has been detected.
@ -506,6 +536,10 @@ 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 */
if (hv_isolation_type_en_snp())
ms_hyperv.vtl = get_vtl();
return;
clean_guest_os_id:

7
arch/x86/include/asm/hyperv-tlfs.h
View File

@ -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,

1
drivers/hv/connection.c
View File

@ -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);

1
include/asm-generic/mshyperv.h
View File

@ -54,6 +54,7 @@ struct ms_hyperv_info {
};
};
u64 shared_gpa_boundary;
u8 vtl;
};
extern struct ms_hyperv_info ms_hyperv;
extern bool hv_nested;

4
include/linux/hyperv.h
View File

@ -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;