From 8387ce06d70bbbb97a0c168a52b68268ae0da075 Mon Sep 17 00:00:00 2001 From: Tianyu Lan Date: Fri, 18 Aug 2023 06:29:12 -0400 Subject: [PATCH] x86/hyperv: Set Virtual Trust Level in VMBus init message 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 Reviewed-by: Michael Kelley Signed-off-by: Tianyu Lan Signed-off-by: Wei Liu Link: https://lore.kernel.org/r/20230818102919.1318039-3-ltykernel@gmail.com --- arch/x86/hyperv/hv_init.c | 34 ++++++++++++++++++++++++++++++ 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, 45 insertions(+), 2 deletions(-) diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 6c04b52f139b..318010eb9f9e 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -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: 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 580c766958de..efd0d2aedad3 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -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; 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;