[PATCH v6 20/76] x86/boot/compressed/64: Call set_sev_encryption_mask earlier
From: Joerg Roedel <joro@8bytes.org>
Date: 2020-08-24 09:16:05
Also in:
kvm, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Joerg Roedel <redacted> Call set_sev_encryption_mask() while still on the stage 1 #VC-handler, because the stage 2 handler needs our own page-tables to be set up, to which calling set_sev_encryption_mask() is a prerequisite. Signed-off-by: Joerg Roedel <redacted> Link: https://lore.kernel.org/r/20200724160336.5435-20-joro@8bytes.org (local) --- arch/x86/boot/compressed/head_64.S | 8 +++++++- arch/x86/boot/compressed/ident_map_64.c | 3 --- 2 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 013b29921836..c7fcf60cbd08 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S@@ -533,9 +533,15 @@ 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 our 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 62e42c11a336..b4f2a5f503cd 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;
--
2.28.0
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