The following commit has been merged into the x86/seves branch of tip: Commit-ID: c2a0304a286f386e45cea3f4b0617f0813de67fd Gitweb: https://git.kernel.org/tip/c2a0304a286f386e45cea3f4b0617f0813de67fd Author: Joerg Roedel <jroe...@suse.de> AuthorDate: Mon, 07 Sep 2020 15:15:21 +02:00 Committer: Borislav Petkov <b...@suse.de> CommitterDate: Mon, 07 Sep 2020 19:45:25 +02:00
x86/boot/compressed/64: Call set_sev_encryption_mask() earlier Call set_sev_encryption_mask() while still on the stage 1 #VC-handler because the stage 2 handler needs the kernel's own page tables to be set up, to which calling set_sev_encryption_mask() is a prerequisite. Signed-off-by: Joerg Roedel <jroe...@suse.de> Signed-off-by: Borislav Petkov <b...@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-21-j...@8bytes.org --- arch/x86/boot/compressed/head_64.S | 9 ++++++++- arch/x86/boot/compressed/ident_map_64.c | 3 --- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index fb6c039..42190c0 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -543,9 +543,16 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) rep stosq /* - * Load stage2 IDT and switch to our own page-table + * If running as an SEV guest, the encryption mask is required in the + * page-table setup code below. When the guest also has SEV-ES enabled + * set_sev_encryption_mask() will cause #VC exceptions, but the stage2 + * handler can't map its GHCB because the page-table is not set up yet. + * So set up the encryption mask here while still on the stage1 #VC + * handler. Then load stage2 IDT and switch to the kernel's own + * page-table. */ pushq %rsi + call set_sev_encryption_mask call load_stage2_idt call initialize_identity_maps popq %rsi diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c index 62e42c1..b4f2a5f 100644 --- a/arch/x86/boot/compressed/ident_map_64.c +++ b/arch/x86/boot/compressed/ident_map_64.c @@ -105,9 +105,6 @@ static void add_identity_map(unsigned long start, unsigned long end) /* Locates and clears a region for a new top level page table. */ void initialize_identity_maps(void) { - /* If running as an SEV guest, the encryption mask is required. */ - set_sev_encryption_mask(); - /* Exclude the encryption mask from __PHYSICAL_MASK */ physical_mask &= ~sme_me_mask;
