From: Tianyu Lan <tiala@xxxxxxxxxxxxx> In the AMD SEV-SNP guest, AP needs to be started up via sev es save area and Hyper-V requires to call HVCALL_START_VP hypercall to pass the gpa of sev es save area with AP's vp index and VTL(Virtual trust level) parameters. Override wakeup_secondary_cpu_64 callback with hv_snp_boot_ap. Signed-off-by: Tianyu Lan <tiala@xxxxxxxxxxxxx> --- arch/x86/hyperv/ivm.c | 95 +++++++++++++++++++++++++++++++ arch/x86/include/asm/mshyperv.h | 9 +++ arch/x86/kernel/cpu/mshyperv.c | 13 ++++- include/asm-generic/hyperv-tlfs.h | 1 + 4 files changed, 116 insertions(+), 2 deletions(-) diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c index b1639ec07155..9b307f99b540 100644 --- a/arch/x86/hyperv/ivm.c +++ b/arch/x86/hyperv/ivm.c @@ -22,11 +22,15 @@ #include <asm/sev.h> #include <asm/realmode.h> #include <asm/e820/api.h> +#include <asm/desc.h> #ifdef CONFIG_AMD_MEM_ENCRYPT #define GHCB_USAGE_HYPERV_CALL 1 +static u8 ap_start_input_arg[PAGE_SIZE] __bss_decrypted __aligned(PAGE_SIZE); +static u8 ap_start_stack[PAGE_SIZE] __aligned(PAGE_SIZE); + union hv_ghcb { struct ghcb ghcb; struct { @@ -449,6 +453,97 @@ __init void hv_sev_init_mem_and_cpu(void) } } +#define hv_populate_vmcb_seg(seg, gdtr_base) \ +do { \ + if (seg.selector) { \ + seg.base = 0; \ + seg.limit = HV_AP_SEGMENT_LIMIT; \ + seg.attrib = *(u16 *)(gdtr_base + seg.selector + 5); \ + seg.attrib = (seg.attrib & 0xFF) | ((seg.attrib >> 4) & 0xF00); \ + } \ +} while (0) \ + +int hv_snp_boot_ap(int cpu, unsigned long start_ip) +{ + struct sev_es_save_area *vmsa = (struct sev_es_save_area *) + __get_free_page(GFP_KERNEL | __GFP_ZERO); + struct desc_ptr gdtr; + u64 ret, rmp_adjust, retry = 5; + struct hv_enable_vp_vtl *start_vp_input; + unsigned long flags; + + native_store_gdt(&gdtr); + + vmsa->gdtr.base = gdtr.address; + vmsa->gdtr.limit = gdtr.size; + + asm volatile("movl %%es, %%eax;" : "=a" (vmsa->es.selector)); + hv_populate_vmcb_seg(vmsa->es, vmsa->gdtr.base); + + asm volatile("movl %%cs, %%eax;" : "=a" (vmsa->cs.selector)); + hv_populate_vmcb_seg(vmsa->cs, vmsa->gdtr.base); + + asm volatile("movl %%ss, %%eax;" : "=a" (vmsa->ss.selector)); + hv_populate_vmcb_seg(vmsa->ss, vmsa->gdtr.base); + + asm volatile("movl %%ds, %%eax;" : "=a" (vmsa->ds.selector)); + hv_populate_vmcb_seg(vmsa->ds, vmsa->gdtr.base); + + vmsa->efer = native_read_msr(MSR_EFER); + + asm volatile("movq %%cr4, %%rax;" : "=a" (vmsa->cr4)); + asm volatile("movq %%cr3, %%rax;" : "=a" (vmsa->cr3)); + asm volatile("movq %%cr0, %%rax;" : "=a" (vmsa->cr0)); + + vmsa->xcr0 = 1; + vmsa->g_pat = HV_AP_INIT_GPAT_DEFAULT; + vmsa->rip = (u64)secondary_startup_64_no_verify; + vmsa->rsp = (u64)&ap_start_stack[PAGE_SIZE]; + + /* + * Set the SNP-specific fields for this VMSA: + * VMPL level + * SEV_FEATURES (matches the SEV STATUS MSR right shifted 2 bits) + */ + vmsa->vmpl = 0; + vmsa->sev_features = sev_status >> 2; + + /* + * Running at VMPL0 allows the kernel to change the VMSA bit for a page + * using the RMPADJUST instruction. However, for the instruction to + * succeed it must target the permissions of a lesser privileged + * (higher numbered) VMPL level, so use VMPL1 (refer to the RMPADJUST + * instruction in the AMD64 APM Volume 3). + */ + rmp_adjust = RMPADJUST_VMSA_PAGE_BIT | 1; + ret = rmpadjust((unsigned long)vmsa, RMP_PG_SIZE_4K, + rmp_adjust); + if (ret != 0) { + pr_err("RMPADJUST(%llx) failed: %llx\n", (u64)vmsa, ret); + return ret; + } + + local_irq_save(flags); + start_vp_input = + (struct hv_enable_vp_vtl *)ap_start_input_arg; + memset(start_vp_input, 0, sizeof(*start_vp_input)); + start_vp_input->partition_id = -1; + start_vp_input->vp_index = cpu; + start_vp_input->target_vtl.target_vtl = ms_hyperv.vtl; + *(u64 *)&start_vp_input->vp_context = __pa(vmsa) | 1; + + do { + ret = hv_do_hypercall(HVCALL_START_VP, + start_vp_input, NULL); + } while (hv_result(ret) == HV_STATUS_TIME_OUT && retry--); + + local_irq_restore(flags); + + if (!hv_result_success(ret)) + pr_err("HvCallStartVirtualProcessor failed: %llx\n", ret); + return ret; +} + void __init hv_vtom_init(void) { /* diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 7a9a6cdc2ae9..804c67475054 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -65,6 +65,13 @@ struct memory_map_entry { u32 reserved; }; +/* + * DEFAULT INIT GPAT and SEGMENT LIMIT value in struct VMSA + * to start AP in enlightened SEV guest. + */ +#define HV_AP_INIT_GPAT_DEFAULT 0x0007040600070406ULL +#define HV_AP_SEGMENT_LIMIT 0xffffffff + int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages); int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id); int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags); @@ -271,6 +278,7 @@ bool hv_ghcb_negotiate_protocol(void); void __noreturn hv_ghcb_terminate(unsigned int set, unsigned int reason); void hv_vtom_init(void); void hv_sev_init_mem_and_cpu(void); +int hv_snp_boot_ap(int cpu, unsigned long start_ip); #else static inline void hv_ghcb_msr_write(u64 msr, u64 value) {} static inline void hv_ghcb_msr_read(u64 msr, u64 *value) {} @@ -278,6 +286,7 @@ static inline bool hv_ghcb_negotiate_protocol(void) { return false; } static inline void hv_ghcb_terminate(unsigned int set, unsigned int reason) {} static inline void hv_vtom_init(void) {} static inline void hv_sev_init_mem_and_cpu(void) {} +static int hv_snp_boot_ap(int cpu, unsigned long start_ip) {} #endif extern bool hv_isolation_type_snp(void); diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index d3bb921ee7fe..8e1d9ed6a1e0 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -295,6 +295,16 @@ static void __init hv_smp_prepare_cpus(unsigned int max_cpus) native_smp_prepare_cpus(max_cpus); + /* + * Override wakeup_secondary_cpu_64 callback for SEV-SNP + * enlightened guest. + */ + if (hv_isolation_type_en_snp()) + apic->wakeup_secondary_cpu_64 = hv_snp_boot_ap; + + if (!hv_root_partition) + return; + #ifdef CONFIG_X86_64 for_each_present_cpu(i) { if (i == 0) @@ -502,8 +512,7 @@ static void __init ms_hyperv_init_platform(void) # ifdef CONFIG_SMP smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu; - if (hv_root_partition) - smp_ops.smp_prepare_cpus = hv_smp_prepare_cpus; + smp_ops.smp_prepare_cpus = hv_smp_prepare_cpus; # endif /* diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h index f4e4cc4f965f..fdac4a1714ec 100644 --- a/include/asm-generic/hyperv-tlfs.h +++ b/include/asm-generic/hyperv-tlfs.h @@ -223,6 +223,7 @@ enum HV_GENERIC_SET_FORMAT { #define HV_STATUS_INVALID_PORT_ID 17 #define HV_STATUS_INVALID_CONNECTION_ID 18 #define HV_STATUS_INSUFFICIENT_BUFFERS 19 +#define HV_STATUS_TIME_OUT 120 #define HV_STATUS_VTL_ALREADY_ENABLED 134 /* -- 2.25.1