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| author | Joerg Roedel <jroedel@suse.de> | 2020-09-07 15:15:43 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-09-09 11:33:19 +0200 |
| commit | 02772fb9b68e6a72a5e17f994048df832fe2b15e (patch) | |
| tree | ac6c3c2e41d924a7ddd9bbce6d605b0790dbc978 /arch/x86/kernel/cpu | |
| parent | 885689e47dfa1499b756a07237eb645234d93cf9 (diff) | |
| download | linux-stable-02772fb9b68e6a72a5e17f994048df832fe2b15e.tar.gz linux-stable-02772fb9b68e6a72a5e17f994048df832fe2b15e.tar.bz2 linux-stable-02772fb9b68e6a72a5e17f994048df832fe2b15e.zip | |
x86/sev-es: Allocate and map an IST stack for #VC handler
Allocate and map an IST stack and an additional fall-back stack for
the #VC handler. The memory for the stacks is allocated only when
SEV-ES is active.
The #VC handler needs to use an IST stack because a #VC exception can be
raised from kernel space with unsafe stack, e.g. in the SYSCALL entry
path.
Since the #VC exception can be nested, the #VC handler switches back to
the interrupted stack when entered from kernel space. If switching back
is not possible, the fall-back stack is used.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200907131613.12703-43-joro@8bytes.org
Diffstat (limited to 'arch/x86/kernel/cpu')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index c5d6f17d9b9d..81fba4d4a242 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1829,6 +1829,8 @@ static inline void tss_setup_ist(struct tss_struct *tss) tss->x86_tss.ist[IST_INDEX_NMI] = __this_cpu_ist_top_va(NMI); tss->x86_tss.ist[IST_INDEX_DB] = __this_cpu_ist_top_va(DB); tss->x86_tss.ist[IST_INDEX_MCE] = __this_cpu_ist_top_va(MCE); + /* Only mapped when SEV-ES is active */ + tss->x86_tss.ist[IST_INDEX_VC] = __this_cpu_ist_top_va(VC); } #else /* CONFIG_X86_64 */ |