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Diffstat (limited to 'arch/x86/mm/mem_encrypt_amd.c')
-rw-r--r--arch/x86/mm/mem_encrypt_amd.c19
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/x86/mm/mem_encrypt_amd.c b/arch/x86/mm/mem_encrypt_amd.c
index e0b51c09109f..54bbd5163e8d 100644
--- a/arch/x86/mm/mem_encrypt_amd.c
+++ b/arch/x86/mm/mem_encrypt_amd.c
@@ -319,7 +319,7 @@ static void enc_dec_hypercall(unsigned long vaddr, int npages, bool enc)
#endif
}
-static void amd_enc_status_change_prepare(unsigned long vaddr, int npages, bool enc)
+static bool amd_enc_status_change_prepare(unsigned long vaddr, int npages, bool enc)
{
/*
* To maintain the security guarantees of SEV-SNP guests, make sure
@@ -327,6 +327,8 @@ static void amd_enc_status_change_prepare(unsigned long vaddr, int npages, bool
*/
if (cc_platform_has(CC_ATTR_GUEST_SEV_SNP) && !enc)
snp_set_memory_shared(vaddr, npages);
+
+ return true;
}
/* Return true unconditionally: return value doesn't matter for the SEV side */
@@ -501,6 +503,21 @@ void __init sme_early_init(void)
x86_platform.guest.enc_status_change_finish = amd_enc_status_change_finish;
x86_platform.guest.enc_tlb_flush_required = amd_enc_tlb_flush_required;
x86_platform.guest.enc_cache_flush_required = amd_enc_cache_flush_required;
+
+ /*
+ * AMD-SEV-ES intercepts the RDMSR to read the X2APIC ID in the
+ * parallel bringup low level code. That raises #VC which cannot be
+ * handled there.
+ * It does not provide a RDMSR GHCB protocol so the early startup
+ * code cannot directly communicate with the secure firmware. The
+ * alternative solution to retrieve the APIC ID via CPUID(0xb),
+ * which is covered by the GHCB protocol, is not viable either
+ * because there is no enforcement of the CPUID(0xb) provided
+ * "initial" APIC ID to be the same as the real APIC ID.
+ * Disable parallel bootup.
+ */
+ if (sev_status & MSR_AMD64_SEV_ES_ENABLED)
+ x86_cpuinit.parallel_bringup = false;
}
void __init mem_encrypt_free_decrypted_mem(void)