| Message ID | 20200211135256.24617-36-joro@8bytes.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Linux as SEV-ES Guest Support | expand |
On Tue, Feb 11, 2020 at 5:53 AM Joerg Roedel <joro@8bytes.org> wrote: > > From: Tom Lendacky <thomas.lendacky@amd.com> > > The runtime handler needs a GHCB per CPU. Set them up and map them > unencrypted. > > Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> > Signed-off-by: Joerg Roedel <jroedel@suse.de> > --- > arch/x86/include/asm/mem_encrypt.h | 2 ++ > arch/x86/kernel/sev-es.c | 25 ++++++++++++++++++++++++- > arch/x86/kernel/traps.c | 3 +++ > 3 files changed, 29 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h > index 6f61bb93366a..d48e7be9bb49 100644 > --- a/arch/x86/include/asm/mem_encrypt.h > +++ b/arch/x86/include/asm/mem_encrypt.h > @@ -48,6 +48,7 @@ int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size); > void __init mem_encrypt_init(void); > void __init mem_encrypt_free_decrypted_mem(void); > > +void __init encrypted_state_init_ghcbs(void); > bool sme_active(void); > bool sev_active(void); > bool sev_es_active(void); > @@ -71,6 +72,7 @@ static inline void __init sme_early_init(void) { } > static inline void __init sme_encrypt_kernel(struct boot_params *bp) { } > static inline void __init sme_enable(struct boot_params *bp) { } > > +static inline void encrypted_state_init_ghcbs(void) { } > static inline bool sme_active(void) { return false; } > static inline bool sev_active(void) { return false; } > static inline bool sev_es_active(void) { return false; } > diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c > index 0e0b28477627..9a5530857db7 100644 > --- a/arch/x86/kernel/sev-es.c > +++ b/arch/x86/kernel/sev-es.c > @@ -8,8 +8,11 @@ > */ > > #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/set_memory.h> > +#include <linux/kernel.h> > #include <linux/mm.h> > > #include <asm/trap_defs.h> > @@ -28,6 +31,9 @@ struct ghcb boot_ghcb_page __bss_decrypted __aligned(PAGE_SIZE); > */ > struct ghcb __initdata *boot_ghcb; > > +/* Runtime GHCBs */ > +static DEFINE_PER_CPU_DECRYPTED(struct ghcb, ghcb_page) __aligned(PAGE_SIZE); Hmm. This is a largeish amount of memory on large non-SEV-ES systems. Maybe store a pointer instead? It would be even better if it could be DEFINE_PER_CPU like this but be discarded if we don't need it, but I don't think we have the infrastructure for that. --Andy
On Tue, Feb 11, 2020 at 02:46:11PM -0800, Andy Lutomirski wrote: > On Tue, Feb 11, 2020 at 5:53 AM Joerg Roedel <joro@8bytes.org> wrote: > > +/* Runtime GHCBs */ > > +static DEFINE_PER_CPU_DECRYPTED(struct ghcb, ghcb_page) __aligned(PAGE_SIZE); > > Hmm. This is a largeish amount of memory on large non-SEV-ES systems. > Maybe store a pointer instead? It would be even better if it could be > DEFINE_PER_CPU like this but be discarded if we don't need it, but I > don't think we have the infrastructure for that. Yeah, discarding is not easily possible right now, but I changed it to only store a pointer and allocating the pages only when running as an SEV-ES guest. Regards, Joerg
diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h index 6f61bb93366a..d48e7be9bb49 100644 --- a/arch/x86/include/asm/mem_encrypt.h +++ b/arch/x86/include/asm/mem_encrypt.h @@ -48,6 +48,7 @@ int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size); void __init mem_encrypt_init(void); void __init mem_encrypt_free_decrypted_mem(void); +void __init encrypted_state_init_ghcbs(void); bool sme_active(void); bool sev_active(void); bool sev_es_active(void); @@ -71,6 +72,7 @@ static inline void __init sme_early_init(void) { } static inline void __init sme_encrypt_kernel(struct boot_params *bp) { } static inline void __init sme_enable(struct boot_params *bp) { } +static inline void encrypted_state_init_ghcbs(void) { } static inline bool sme_active(void) { return false; } static inline bool sev_active(void) { return false; } static inline bool sev_es_active(void) { return false; } diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c index 0e0b28477627..9a5530857db7 100644 --- a/arch/x86/kernel/sev-es.c +++ b/arch/x86/kernel/sev-es.c @@ -8,8 +8,11 @@ */ #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/set_memory.h> +#include <linux/kernel.h> #include <linux/mm.h> #include <asm/trap_defs.h> @@ -28,6 +31,9 @@ struct ghcb boot_ghcb_page __bss_decrypted __aligned(PAGE_SIZE); */ struct ghcb __initdata *boot_ghcb; +/* Runtime GHCBs */ +static DEFINE_PER_CPU_DECRYPTED(struct ghcb, ghcb_page) __aligned(PAGE_SIZE); + /* Needed in early_forward_exception */ extern void early_exception(struct pt_regs *regs, int trapnr); @@ -133,6 +139,23 @@ static bool __init setup_ghcb(void) return true; } +void encrypted_state_init_ghcbs(void) +{ + int cpu; + + if (!sev_es_active()) + return; + + /* Initialize per-cpu GHCB pages */ + for_each_possible_cpu(cpu) { + struct ghcb *ghcb = &per_cpu(ghcb_page, cpu); + + set_memory_decrypted((unsigned long)ghcb, + sizeof(ghcb_page) >> PAGE_SHIFT); + memset(ghcb, 0, sizeof(*ghcb)); + } +} + static void __init 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 6ef00eb6fbb9..9c9a7fae36d3 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -918,6 +918,9 @@ 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 */ + encrypted_state_init_ghcbs(); + idt_setup_traps(); /*