From: Tianyu Lan <ltykernel@xxxxxxxxx> Sent: Monday, June 26, 2023 8:23 PM > > Hyper-V enlightened guest doesn't have boot loader support. > Boot Linux kernel directly from hypervisor with data (kernel > image, initrd and parameter page) and memory for boot up that > is initialized via AMD SEV PSP protocol (Please reference > Section 4.5 Launching a Guest of [1]). > > Kernel needs to read processor and memory info from EN_SEV_ > SNP_PROCESSOR/MEM_INFO_ADDR address which are populated by > Hyper-V. The these data is prepared by hypervisor via SNP_ s/The these data/The data/ > LAUNCH_UPDATE with page type SNP_PAGE_TYPE_UNMEASURED and > Initialize smp cpu related ops, validate system memory and > add them into e820 table. > > [1]: https://www.amd.com/system/files/TechDocs/56860.pdf > Signed-off-by: Tianyu Lan <tiala@xxxxxxxxxxxxx> > --- > arch/x86/hyperv/ivm.c | 93 +++++++++++++++++++++++++++++++++ > arch/x86/include/asm/mshyperv.h | 17 ++++++ > arch/x86/kernel/cpu/mshyperv.c | 3 ++ > 3 files changed, 113 insertions(+) > > diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c > index 5d3ee3124e00..b1639ec07155 100644 > --- a/arch/x86/hyperv/ivm.c > +++ b/arch/x86/hyperv/ivm.c > @@ -17,6 +17,11 @@ > #include <asm/mem_encrypt.h> > #include <asm/mshyperv.h> > #include <asm/hypervisor.h> > +#include <asm/coco.h> > +#include <asm/io_apic.h> > +#include <asm/sev.h> > +#include <asm/realmode.h> > +#include <asm/e820/api.h> > > #ifdef CONFIG_AMD_MEM_ENCRYPT > > @@ -57,6 +62,8 @@ union hv_ghcb { > > static u16 hv_ghcb_version __ro_after_init; > > +static u32 processor_count; > + > u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size) > { > union hv_ghcb *hv_ghcb; > @@ -356,6 +363,92 @@ static bool hv_is_private_mmio(u64 addr) > return false; > } > > +static __init void hv_snp_get_smp_config(unsigned int early) > +{ > + /* > + * The "early" parameter can be true only if old-style AMD > + * Opteron NUMA detection is enabled, which should never be > + * the case for an SEV-SNP guest. See CONFIG_AMD_NUMA. > + * For safety, just do nothing if "early" is true. > + */ > + if (early) > + return; > + > + /* > + * There is no firmware and ACPI MADT table support in > + * in the Hyper-V SEV-SNP enlightened guest. Set smp > + * related config variable here. > + */ > + while (num_processors < processor_count) { > + early_per_cpu(x86_cpu_to_apicid, num_processors) = num_processors; > + early_per_cpu(x86_bios_cpu_apicid, num_processors) = num_processors; > + physid_set(num_processors, phys_cpu_present_map); > + set_cpu_possible(num_processors, true); > + set_cpu_present(num_processors, true); > + num_processors++; > + } > +} > + > +__init void hv_sev_init_mem_and_cpu(void) > +{ > + struct memory_map_entry *entry; > + struct e820_entry *e820_entry; > + u64 e820_end; > + u64 ram_end; > + u64 page; > + > + /* > + * Hyper-V enlightened snp guest boots kernel > + * directly without bootloader. So roms, bios > + * regions and reserve resources are not available. > + * Set these callback to NULL. > + */ > + x86_platform.legacy.rtc = 0; > + x86_platform.legacy.reserve_bios_regions = 0; > + x86_platform.set_wallclock = set_rtc_noop; > + x86_platform.get_wallclock = get_rtc_noop; > + x86_init.resources.probe_roms = x86_init_noop; > + x86_init.resources.reserve_resources = x86_init_noop; > + x86_init.mpparse.find_smp_config = x86_init_noop; > + x86_init.mpparse.get_smp_config = hv_snp_get_smp_config; > + > + /* > + * Hyper-V SEV-SNP enlightened guest doesn't support ioapic > + * and legacy APIC page read/write. Switch to hv apic here. > + */ > + disable_ioapic_support(); > + > + /* Get processor and mem info. */ > + processor_count = *(u32 *)__va(EN_SEV_SNP_PROCESSOR_INFO_ADDR); > + entry = (struct memory_map_entry *)__va(EN_SEV_SNP_MEM_INFO_ADDR); > + > + /* > + * There is no bootloader/EFI firmware in the SEV SNP guest. > + * E820 table in the memory just describes memory for kernel, > + * ACPI table, cmdline, boot params and ramdisk. The dynamic > + * data(e.g, vcpu number and the rest memory layout) needs to > + * be read from EN_SEV_SNP_PROCESSOR_INFO_ADDR. > + */ > + for (; entry->numpages != 0; entry++) { > + e820_entry = &e820_table->entries[ > + e820_table->nr_entries - 1]; > + e820_end = e820_entry->addr + e820_entry->size; > + ram_end = (entry->starting_gpn + > + entry->numpages) * PAGE_SIZE; > + > + if (e820_end < entry->starting_gpn * PAGE_SIZE) > + e820_end = entry->starting_gpn * PAGE_SIZE; > + > + if (e820_end < ram_end) { > + pr_info("Hyper-V: add e820 entry [mem %#018Lx-%#018Lx]\n", e820_end, ram_end - 1); > + e820__range_add(e820_end, ram_end - e820_end, > + E820_TYPE_RAM); > + for (page = e820_end; page < ram_end; page += PAGE_SIZE) > + pvalidate((unsigned long)__va(page), RMP_PG_SIZE_4K, true); > + } > + } > +} > + > void __init hv_vtom_init(void) > { > /* > diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h > index d859d7c5f5e8..7a9a6cdc2ae9 100644 > --- a/arch/x86/include/asm/mshyperv.h > +++ b/arch/x86/include/asm/mshyperv.h > @@ -50,6 +50,21 @@ extern bool hv_isolation_type_en_snp(void); > > extern union hv_ghcb * __percpu *hv_ghcb_pg; > > +/* > + * Hyper-V puts processor and memory layout info > + * to this address in SEV-SNP enlightened guest. > + */ > +#define EN_SEV_SNP_PROCESSOR_INFO_ADDR 0x802000 > +#define EN_SEV_SNP_MEM_INFO_ADDR 0x802018 > + > +struct memory_map_entry { > + u64 starting_gpn; > + u64 numpages; > + u16 type; > + u16 flags; > + u32 reserved; > +}; > + > 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); > @@ -255,12 +270,14 @@ void hv_ghcb_msr_read(u64 msr, u64 *value); > 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); > #else > static inline void hv_ghcb_msr_write(u64 msr, u64 value) {} > static inline void hv_ghcb_msr_read(u64 msr, u64 *value) {} > 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) {} > #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 5398fb2f4d39..d3bb921ee7fe 100644 > --- a/arch/x86/kernel/cpu/mshyperv.c > +++ b/arch/x86/kernel/cpu/mshyperv.c > @@ -529,6 +529,9 @@ static void __init ms_hyperv_init_platform(void) > if (!(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT)) > mark_tsc_unstable("running on Hyper-V"); > > + if (hv_isolation_type_en_snp()) > + hv_sev_init_mem_and_cpu(); > + > hardlockup_detector_disable(); > } > > -- > 2.25.1 Modulo spurious word in the commit message, Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
