[PATCH v6 10/10] x86/sev: Exclude AP jump table related code for SEV-SNP guests
From: <hidden>
Date: 2024-06-10 10:21:45
Also in:
kexec, kvm, linux-coco, lkml, stable
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Vasant Karasulli <redacted> Unlike SEV-ES, AP jump table technique is not used in SEV-SNP when transitioning from one layer of code to another (e.g. when going from UEFI to the OS). Signed-off-by: Vasant Karasulli <redacted> --- arch/x86/kernel/sev.c | 6 +++++- arch/x86/realmode/init.c | 5 +++-- 2 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index e64320507da2..a9cf74512269 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c@@ -1392,7 +1392,8 @@ STACK_FRAME_NON_STANDARD(sev_jumptable_ap_park); void sev_es_stop_this_cpu(void) { if (!(cc_vendor == CC_VENDOR_AMD) || - !cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) + !cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT) || + cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) return; /* Only park in the AP jump table when the code has been installed */
@@ -1468,6 +1469,9 @@ bool sev_kexec_supported(void) if (!cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) return true; + if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) + return false; + /* * KEXEC with SEV-ES and more than one CPU is only supported * when the AP jump table is installed.
diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index f9bc444a3064..ed798939be5d 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c@@ -80,8 +80,9 @@ static void __init sme_sev_setup_real_mode(struct trampoline_header *th) */ th->start = (u64) secondary_startup_64_no_verify; - if (sev_es_setup_ap_jump_table(real_mode_header)) - panic("Failed to get/update SEV-ES AP Jump Table"); + if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) + if (sev_es_setup_ap_jump_table(real_mode_header)) + panic("Failed to get/update SEV-ES AP Jump Table"); } #endif }
--
2.34.1