diff options
| author | Tom Lendacky <thomas.lendacky@amd.com> | 2020-09-07 15:15:42 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-09-09 11:33:19 +0200 |
| commit | 885689e47dfa1499b756a07237eb645234d93cf9 (patch) | |
| tree | ad37684b76cb072a208d392192532eeb5fa736e0 /arch/x86/kernel | |
| parent | 1aa9aa8ee517e0443b06e816a4fd2d15f2113615 (diff) | |
x86/sev-es: Setup per-CPU GHCBs for the runtime handler
The runtime handler needs one GHCB per-CPU. Set them up and map them
unencrypted.
[ bp: Touchups and simplification. ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200907131613.12703-42-joro@8bytes.org
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/sev-es.c | 56 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 3 |
2 files changed, 58 insertions, 1 deletions
diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c index 213a42774aa9..720b1b671812 100644 --- a/arch/x86/kernel/sev-es.c +++ b/arch/x86/kernel/sev-es.c @@ -8,8 +8,13 @@ */ #include <linux/sched/debug.h> /* For show_regs() */ -#include <linux/kernel.h> +#include <linux/percpu-defs.h> +#include <linux/mem_encrypt.h> #include <linux/printk.h> +#include <linux/mm_types.h> +#include <linux/set_memory.h> +#include <linux/memblock.h> +#include <linux/kernel.h> #include <linux/mm.h> #include <asm/sev-es.h> @@ -29,6 +34,13 @@ static struct ghcb boot_ghcb_page __bss_decrypted __aligned(PAGE_SIZE); */ static struct ghcb __initdata *boot_ghcb; +/* #VC handler runtime per-CPU data */ +struct sev_es_runtime_data { + struct ghcb ghcb_page; +}; + +static DEFINE_PER_CPU(struct sev_es_runtime_data*, runtime_data); + /* Needed in vc_early_forward_exception */ void do_early_exception(struct pt_regs *regs, int trapnr); @@ -198,6 +210,48 @@ static bool __init sev_es_setup_ghcb(void) return true; } +static void __init alloc_runtime_data(int cpu) +{ + struct sev_es_runtime_data *data; + + data = memblock_alloc(sizeof(*data), PAGE_SIZE); + if (!data) + panic("Can't allocate SEV-ES runtime data"); + + per_cpu(runtime_data, cpu) = data; +} + +static void __init init_ghcb(int cpu) +{ + struct sev_es_runtime_data *data; + int err; + + data = per_cpu(runtime_data, cpu); + + err = early_set_memory_decrypted((unsigned long)&data->ghcb_page, + sizeof(data->ghcb_page)); + if (err) + panic("Can't map GHCBs unencrypted"); + + memset(&data->ghcb_page, 0, sizeof(data->ghcb_page)); +} + +void __init sev_es_init_vc_handling(void) +{ + int cpu; + + BUILD_BUG_ON(offsetof(struct sev_es_runtime_data, ghcb_page) % PAGE_SIZE); + + if (!sev_es_active()) + return; + + /* Initialize per-cpu GHCB pages */ + for_each_possible_cpu(cpu) { + alloc_runtime_data(cpu); + init_ghcb(cpu); + } +} + static void __init vc_early_forward_exception(struct es_em_ctxt *ctxt) { int trapnr = ctxt->fi.vector; diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 81a2fb711091..2dc32b0ca38e 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -1074,6 +1074,9 @@ void __init trap_init(void) /* Init cpu_entry_area before IST entries are set up */ setup_cpu_entry_areas(); + /* Init GHCB memory pages when running as an SEV-ES guest */ + sev_es_init_vc_handling(); + idt_setup_traps(); /* |