x86/sev: Carve out the SVSM support code

PATCH Applied Borislav Petkov 4 participants 10 messages Dec 4, 2025 – Dec 31, 2025 x86

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Borislav Petkov

author

2025-12-04 12:48 UTC #0 lore raw

cover x86/sev: Carve out the SVSM support code

From: "Borislav Petkov (AMD)" <[email protected]>

Hi,

I've been meaning to do this for a while now but didn't have a good idea how to do it nicely. Using the internal header makes it almost trivial.

Thx.

Borislav Petkov (AMD) (3):
x86/sev: Move the internal header
x86/sev: Add internal header guards
x86/sev: Carve out the SVSM code into a separate compilation unit

 arch/x86/boot/startup/sev-startup.c           |   3 +-
 arch/x86/coco/sev/Makefile                    |   2 +-
 arch/x86/coco/sev/core.c                      | 380 +-----------------
 .../sev-internal.h => coco/sev/internal.h}    |  32 ++
 arch/x86/coco/sev/noinstr.c                   |   3 +-
 arch/x86/coco/sev/svsm.c                      | 362 +++++++++++++++++
 arch/x86/coco/sev/vc-handle.c                 |   3 +-
 7 files changed, 403 insertions(+), 382 deletions(-)
 rename arch/x86/{include/asm/sev-internal.h => coco/sev/internal.h} (75%)
 create mode 100644 arch/x86/coco/sev/svsm.c

Signature · 1 line

2.51.0

Borislav Petkov

author

2025-12-04 12:48 UTC #1 lore raw

PATCH 1/3 x86/sev: Move the internal header

From: "Borislav Petkov (AMD)" <[email protected]>

Move the internal header out of the usual include/asm/ include path because having an "internal" header there doesn't really make it so
- quite the opposite.

So move where it belongs and make it really internal.

No functional changes.

Signed-off-by Borislav Petkov (AMD) <[email protected]>

---
 arch/x86/boot/startup/sev-startup.c                          | 3 ++-
 arch/x86/coco/sev/core.c                                     | 3 ++-
 arch/x86/{include/asm/sev-internal.h => coco/sev/internal.h} | 0
 arch/x86/coco/sev/noinstr.c                                  | 3 ++-
 arch/x86/coco/sev/vc-handle.c                                | 3 ++-
 5 files changed, 8 insertions(+), 4 deletions(-)
 rename arch/x86/{include/asm/sev-internal.h => coco/sev/internal.h} (100%)

arch/x86/boot/startup/sev-startup.c +2 -1

index 09725428d3e6..1115214429fd 100644
@@ -27,7 +27,6 @@
 #include <asm/cpu_entry_area.h>
 #include <asm/stacktrace.h>
 #include <asm/sev.h>
-#include <asm/sev-internal.h>
 #include <asm/insn-eval.h>
 #include <asm/fpu/xcr.h>
 #include <asm/processor.h>

@@ -41,6 +40,8 @@
 #include <asm/cpuid/api.h>
 #include <asm/cmdline.h>
 
+#include "../coco/sev/internal.h"
+
 /* Include code shared with pre-decompression boot stage */
 #include "sev-shared.c"

arch/x86/coco/sev/core.c +2 -1

index 9ae3b11754e6..4e618e596267 100644
@@ -31,7 +31,6 @@
 #include <asm/cpu_entry_area.h>
 #include <asm/stacktrace.h>
 #include <asm/sev.h>
-#include <asm/sev-internal.h>
 #include <asm/insn-eval.h>
 #include <asm/fpu/xcr.h>
 #include <asm/processor.h>

@@ -46,6 +45,8 @@
 #include <asm/cmdline.h>
 #include <asm/msr.h>
 
+#include "internal.h"
+
 /* Bitmap of SEV features supported by the hypervisor */
 u64 sev_hv_features __ro_after_init;
 SYM_PIC_ALIAS(sev_hv_features);

arch/x86/coco/sev/internal.h renamed from arch/x86/include/asm/sev-internal.h +0 -0

similarity index 100%
rename from arch/x86/include/asm/sev-internal.h
rename to arch/x86/coco/sev/internal.h

arch/x86/coco/sev/noinstr.c +2 -1

index b527eafb6312..9d94aca4a698 100644
@@ -16,7 +16,8 @@
 #include <asm/msr.h>
 #include <asm/ptrace.h>
 #include <asm/sev.h>
-#include <asm/sev-internal.h>
+
+#include "internal.h"
 
 static __always_inline bool on_vc_stack(struct pt_regs *regs)
 {

arch/x86/coco/sev/vc-handle.c +2 -1

index f08c7505ed82..43f264afd590 100644
@@ -23,7 +23,6 @@
 #include <asm/init.h>
 #include <asm/stacktrace.h>
 #include <asm/sev.h>
-#include <asm/sev-internal.h>
 #include <asm/insn-eval.h>
 #include <asm/fpu/xcr.h>
 #include <asm/processor.h>

@@ -35,6 +34,8 @@
 #include <asm/apic.h>
 #include <asm/cpuid/api.h>
 
+#include "internal.h"
+
 static enum es_result vc_slow_virt_to_phys(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
 					   unsigned long vaddr, phys_addr_t *paddr)
 {

Signature · 1 line

2.51.0

Tom Lendacky

2025-12-04 14:20 UTC #2 lore raw

Re: [PATCH 1/3] x86/sev: Move the internal header

Quoted 33 lines · Borislav Petkov

From: "Borislav Petkov (AMD)" <[email protected]>
Move the internal header out of the usual include/asm/ include path because having an "internal" header there doesn't really make it so
- quite the opposite.
So move where it belongs and make it really internal.
No functional changes.
Signed-off-by Borislav Petkov (AMD) <[email protected]>
---
 arch/x86/boot/startup/sev-startup.c                          | 3 ++-
 arch/x86/coco/sev/core.c                                     | 3 ++-
 arch/x86/{include/asm/sev-internal.h => coco/sev/internal.h} | 0
 arch/x86/coco/sev/noinstr.c                                  | 3 ++-
 arch/x86/coco/sev/vc-handle.c                                | 3 ++-
 5 files changed, 8 insertions(+), 4 deletions(-)
 rename arch/x86/{include/asm/sev-internal.h => coco/sev/internal.h} (100%)
arch/x86/boot/startup/sev-startup.c +0 -1
index 09725428d3e6..1115214429fd 100644
@@ -27,7 +27,6 @@
 #include <asm/cpu_entry_area.h>
 #include <asm/stacktrace.h>
 #include <asm/sev.h>
-#include <asm/sev-internal.h>
 #include <asm/insn-eval.h>
 #include <asm/fpu/xcr.h>
 #include <asm/processor.h>

arch/x86/boot/startup/sev-startup.c line 43

Quoted 4 lines

arch/x86/boot/startup/sev-startup.c +1 -0

@@ -41,6 +40,8 @@
 #include <asm/cpuid/api.h>
 #include <asm/cmdline.h>
 
+#include "../coco/sev/internal.h"

Shouldn't this be "../../coco/sev/internal.h" ?

What is strange is that it works with either.

Thanks,
Tom

Quoted 64 lines

arch/x86/boot/startup/sev-startup.c +1 -0

+
 /* Include code shared with pre-decompression boot stage */
 #include "sev-shared.c"

arch/x86/coco/sev/core.c +2 -1

index 9ae3b11754e6..4e618e596267 100644
@@ -31,7 +31,6 @@
 #include <asm/cpu_entry_area.h>
 #include <asm/stacktrace.h>
 #include <asm/sev.h>
-#include <asm/sev-internal.h>
 #include <asm/insn-eval.h>
 #include <asm/fpu/xcr.h>
 #include <asm/processor.h>

@@ -46,6 +45,8 @@
 #include <asm/cmdline.h>
 #include <asm/msr.h>
 
+#include "internal.h"
+
 /* Bitmap of SEV features supported by the hypervisor */
 u64 sev_hv_features __ro_after_init;
 SYM_PIC_ALIAS(sev_hv_features);

arch/x86/coco/sev/internal.h renamed from arch/x86/include/asm/sev-internal.h +0 -0

similarity index 100%
rename from arch/x86/include/asm/sev-internal.h
rename to arch/x86/coco/sev/internal.h

arch/x86/coco/sev/noinstr.c +2 -1

index b527eafb6312..9d94aca4a698 100644
@@ -16,7 +16,8 @@
 #include <asm/msr.h>
 #include <asm/ptrace.h>
 #include <asm/sev.h>
-#include <asm/sev-internal.h>
+
+#include "internal.h"
 
 static __always_inline bool on_vc_stack(struct pt_regs *regs)
 {

arch/x86/coco/sev/vc-handle.c +2 -1

index f08c7505ed82..43f264afd590 100644
@@ -23,7 +23,6 @@
 #include <asm/init.h>
 #include <asm/stacktrace.h>
 #include <asm/sev.h>
-#include <asm/sev-internal.h>
 #include <asm/insn-eval.h>
 #include <asm/fpu/xcr.h>
 #include <asm/processor.h>

@@ -35,6 +34,8 @@
 #include <asm/apic.h>
 #include <asm/cpuid/api.h>
 
+#include "internal.h"
+
 static enum es_result vc_slow_virt_to_phys(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
 					   unsigned long vaddr, phys_addr_t *paddr)
 {

Borislav Petkov

maintainer

2025-12-04 14:57 UTC #3 lore raw

Re: [PATCH 1/3] x86/sev: Move the internal header

Quoted 5 lines · Tom Lendacky

Quoted 1 line
+#include "../coco/sev/internal.h"
Shouldn't this be "../../coco/sev/internal.h" ?
What is strange is that it works with either.

Pure luck :-\

gcc cmdline is:

gcc -Wp,-MMD,arch/x86/boot/startup/.sev-startup.o.d -nostdinc -I./arch/x86/include...

so the include path becomes:

# 1 "./arch/x86/include/../coco/sev/internal.h" 1

which is

$ readlink -f  arch/x86/include/../coco/sev/internal.h 
/mnt/kernel/kernel/linux/arch/x86/coco/sev/internal.h

And /mnt/kernel is my kernel-sources-containing SSD :-)

In any case, good catch!

I'll do the "../../" so that it is perfectly clear and future potential include directives changes do not break this.

Thx.

Signature · 4 lines

Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

Borislav Petkov

author

2025-12-04 12:48 UTC #4 lore raw

PATCH 2/3 x86/sev: Add internal header guards

In reply to Borislav Petkov

From: "Borislav Petkov (AMD)" <[email protected]>

All headers need guards ifdeffery.

Signed-off-by Borislav Petkov (AMD) <[email protected]>

---
 arch/x86/coco/sev/internal.h | 3 +++
 1 file changed, 3 insertions(+)

arch/x86/coco/sev/internal.h +3 -0

index c58c47c68ab6..af991f1da095 100644
@@ -1,4 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __X86_COCO_SEV_INTERNAL_H__
+#define __X86_COCO_SEV_INTERNAL_H__
 
 #define DR7_RESET_VALUE        0x400

@@ -85,3 +87,4 @@ enum es_result sev_es_ghcb_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt
 u64 get_hv_features(void);
 
 const struct snp_cpuid_table *snp_cpuid_get_table(void);
+#endif /* __X86_COCO_SEV_INTERNAL_H__ */

Signature · 1 line

2.51.0

tip-bot2 for Borislav Petkov (AMD)

merge bot Applied

2025-12-31 12:25 UTC #5 lore raw

[tip: x86/sev] x86/sev: Add internal header guards

The following commit has been merged into the x86/sev branch of tip:

Commit-ID:     f01c6489ad6ceb8d06eae0c5123fc6cf39276ff1
Gitweb:        https://git.kernel.org/tip/f01c6489ad6ceb8d06eae0c5123fc6cf39276ff1
Author:        Borislav Petkov (AMD) <[email protected]>
AuthorDate:    Thu, 04 Dec 2025 13:48:07 +01:00
Committer:     Borislav Petkov (AMD) <[email protected]>
CommitterDate: Wed, 31 Dec 2025 13:16:06 +01:00

x86/sev: Add internal header guards

All headers need guards ifdeffery.

Reviewed-by Tom Lendacky <[email protected]>

Signed-off-by Borislav Petkov (AMD) <[email protected]>

Link https://patch.msgid.link/[email protected] open here

---
 arch/x86/coco/sev/internal.h | 3 +++
 1 file changed, 3 insertions(+)

arch/x86/coco/sev/internal.h +3 -0

index c58c47c..af991f1 100644
@@ -1,4 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __X86_COCO_SEV_INTERNAL_H__
+#define __X86_COCO_SEV_INTERNAL_H__
 
 #define DR7_RESET_VALUE        0x400

@@ -85,3 +87,4 @@ enum es_result sev_es_ghcb_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt
 u64 get_hv_features(void);
 
 const struct snp_cpuid_table *snp_cpuid_get_table(void);
+#endif /* __X86_COCO_SEV_INTERNAL_H__ */

Borislav Petkov

author

2025-12-04 12:48 UTC #6 lore raw

PATCH 3/3 x86/sev: Carve out the SVSM code into a separate compilation unit

In reply to Borislav Petkov

From: "Borislav Petkov (AMD)" <[email protected]>

Move the SVSM-related machinery into a separate compilation unit in order to keep sev/core.c slim and "on-topic".

No functional changes.

Signed-off-by Borislav Petkov (AMD) <[email protected]>

---
 arch/x86/coco/sev/Makefile   |   2 +-
 arch/x86/coco/sev/core.c     | 377 -----------------------------------
 arch/x86/coco/sev/internal.h |  29 +++
 arch/x86/coco/sev/svsm.c     | 362 +++++++++++++++++++++++++++++++++
 4 files changed, 392 insertions(+), 378 deletions(-)
 create mode 100644 arch/x86/coco/sev/svsm.c

arch/x86/coco/sev/Makefile +1 -1

index 3b8ae214a6a6..fb8ffedfc8b0 100644
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 
-obj-y += core.o noinstr.o vc-handle.o
+obj-y += core.o noinstr.o vc-handle.o svsm.o
 
 # Clang 14 and older may fail to respect __no_sanitize_undefined when inlining
 UBSAN_SANITIZE_noinstr.o	:= n

arch/x86/coco/sev/core.c +0 ~~-377~~

407 lines not on this page · raw message

arch/x86/coco/sev/internal.h +29 -0

index af991f1da095..039326b5c799 100644
@@ -66,6 +66,9 @@ extern u64 boot_svsm_caa_pa;
 
 enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt *ctxt);
 void vc_forward_exception(struct es_em_ctxt *ctxt);
+void svsm_pval_pages(struct snp_psc_desc *desc);
+int svsm_perform_call_protocol(struct svsm_call *call);
+bool snp_svsm_vtpm_probe(void);
 
 static inline u64 sev_es_rd_ghcb_msr(void)
 {

@@ -87,4 +90,30 @@ enum es_result sev_es_ghcb_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt
 u64 get_hv_features(void);
 
 const struct snp_cpuid_table *snp_cpuid_get_table(void);
+
+static inline struct svsm_ca *svsm_get_caa(void)
+{
+	if (sev_cfg.use_cas)
+		return this_cpu_read(svsm_caa);
+	else
+		return rip_rel_ptr(&boot_svsm_ca_page);
+}
+
+static inline u64 svsm_get_caa_pa(void)
+{
+	if (sev_cfg.use_cas)
+		return this_cpu_read(svsm_caa_pa);
+	else
+		return boot_svsm_caa_pa;
+}
+
+static inline void __pval_terminate(u64 pfn, bool action, unsigned int page_size,
+				    int ret, u64 svsm_ret)
+{
+	WARN(1, "PVALIDATE failure: pfn: 0x%llx, action: %u, size: %u, ret: %d, svsm_ret: 0x%llx\n",
+	     pfn, action, page_size, ret, svsm_ret);
+
+	sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
+}
+
 #endif /* __X86_COCO_SEV_INTERNAL_H__ */

arch/x86/coco/sev/svsm.c new file +362 -0

362 lines not on this page · raw message

Signature · 1 line

2.51.0

tip-bot2 for Borislav Petkov (AMD)

merge bot Applied

2025-12-31 12:25 UTC #7 lore raw

[tip: x86/sev] x86/sev: Carve out the SVSM code into a separate compilation unit

The following commit has been merged into the x86/sev branch of tip:

Commit-ID:     e21279b73ef6c7d27237912c914f2db0c5a74786
Gitweb:        https://git.kernel.org/tip/e21279b73ef6c7d27237912c914f2db0c5a74786
Author:        Borislav Petkov (AMD) <[email protected]>
AuthorDate:    Thu, 04 Dec 2025 13:48:08 +01:00
Committer:     Borislav Petkov (AMD) <[email protected]>
CommitterDate: Wed, 31 Dec 2025 13:18:23 +01:00

x86/sev: Carve out the SVSM code into a separate compilation unit

Move the SVSM-related machinery into a separate compilation unit in order to keep sev/core.c slim and "on-topic".

No functional changes.

Reviewed-by Tom Lendacky <[email protected]>

Signed-off-by Borislav Petkov (AMD) <[email protected]>

Link https://patch.msgid.link/[email protected] open here

---
 arch/x86/coco/sev/Makefile   |   2 +-
 arch/x86/coco/sev/core.c     | 377 +----------------------------------
 arch/x86/coco/sev/internal.h |  29 +++-
 arch/x86/coco/sev/svsm.c     | 362 +++++++++++++++++++++++++++++++++-
 4 files changed, 392 insertions(+), 378 deletions(-)
 create mode 100644 arch/x86/coco/sev/svsm.c

arch/x86/coco/sev/Makefile +1 -1

index 3b8ae21..fb8ffed 100644
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 
-obj-y += core.o noinstr.o vc-handle.o
+obj-y += core.o noinstr.o vc-handle.o svsm.o
 
 # Clang 14 and older may fail to respect __no_sanitize_undefined when inlining
 UBSAN_SANITIZE_noinstr.o	:= n

arch/x86/coco/sev/core.c +0 ~~-377~~

407 lines not on this page · raw message

arch/x86/coco/sev/internal.h +29 -0

index af991f1..039326b 100644
@@ -66,6 +66,9 @@ extern u64 boot_svsm_caa_pa;
 
 enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt *ctxt);
 void vc_forward_exception(struct es_em_ctxt *ctxt);
+void svsm_pval_pages(struct snp_psc_desc *desc);
+int svsm_perform_call_protocol(struct svsm_call *call);
+bool snp_svsm_vtpm_probe(void);
 
 static inline u64 sev_es_rd_ghcb_msr(void)
 {

@@ -87,4 +90,30 @@ enum es_result sev_es_ghcb_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt
 u64 get_hv_features(void);
 
 const struct snp_cpuid_table *snp_cpuid_get_table(void);
+
+static inline struct svsm_ca *svsm_get_caa(void)
+{
+	if (sev_cfg.use_cas)
+		return this_cpu_read(svsm_caa);
+	else
+		return rip_rel_ptr(&boot_svsm_ca_page);
+}
+
+static inline u64 svsm_get_caa_pa(void)
+{
+	if (sev_cfg.use_cas)
+		return this_cpu_read(svsm_caa_pa);
+	else
+		return boot_svsm_caa_pa;
+}
+
+static inline void __pval_terminate(u64 pfn, bool action, unsigned int page_size,
+				    int ret, u64 svsm_ret)
+{
+	WARN(1, "PVALIDATE failure: pfn: 0x%llx, action: %u, size: %u, ret: %d, svsm_ret: 0x%llx\n",
+	     pfn, action, page_size, ret, svsm_ret);
+
+	sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE);
+}
+
 #endif /* __X86_COCO_SEV_INTERNAL_H__ */

arch/x86/coco/sev/svsm.c new file +362 -0

362 lines not on this page · raw message

Tom Lendacky

Reviewed-by on the v1 series

2025-12-04 14:53 UTC #8 lore raw

In reply to Borislav Petkov

Quoted 6 lines · Borislav Petkov

From: "Borislav Petkov (AMD)" <[email protected]>
Hi,
I've been meaning to do this for a while now but didn't have a good idea how to do it nicely. Using the internal header makes it almost trivial.

Quick testing doesn't show any issues.

Reviewed-by Tom Lendacky <[email protected]>

Quoted 19 lines

Thx.

Borislav Petkov (AMD) (3):
x86/sev: Move the internal header
x86/sev: Add internal header guards
x86/sev: Carve out the SVSM code into a separate compilation unit

 arch/x86/boot/startup/sev-startup.c           |   3 +-
 arch/x86/coco/sev/Makefile                    |   2 +-
 arch/x86/coco/sev/core.c                      | 380 +-----------------
 .../sev-internal.h => coco/sev/internal.h}    |  32 ++
 arch/x86/coco/sev/noinstr.c                   |   3 +-
 arch/x86/coco/sev/svsm.c                      | 362 +++++++++++++++++
 arch/x86/coco/sev/vc-handle.c                 |   3 +-
 7 files changed, 403 insertions(+), 382 deletions(-)
 rename arch/x86/{include/asm/sev-internal.h => coco/sev/internal.h} (75%)
 create mode 100644 arch/x86/coco/sev/svsm.c

Borislav Petkov

maintainer

2025-12-04 15:06 UTC #9 lore raw

Quoted 3 lines · Tom Lendacky

Quick testing doesn't show any issues.
Reviewed-by Tom Lendacky <[email protected]>

Much appreciated, thanks!

Signature · 4 lines

Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette