5 files changed, 17 insertions, 28 deletions

diff --git a/arch/x86/kernel/eisa.c b/arch/x86/kernel/eisa.c
index e963344b0449..53935b4d62e3 100644
--- a/arch/x86/kernel/eisa.c
+++ b/arch/x86/kernel/eisa.c
@@ -2,6 +2,7 @@
 /*
  * EISA specific code
  */
+#include <linux/cc_platform.h>
 #include <linux/ioport.h>
 #include <linux/eisa.h>
 #include <linux/io.h>
@@ -12,7 +13,7 @@ static __init int eisa_bus_probe(void)
 {
 	void __iomem *p;
 
-	if (xen_pv_domain() && !xen_initial_domain())
+	if ((xen_pv_domain() && !xen_initial_domain()) || cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
 		return 0;
 
 	p = ioremap(0x0FFFD9, 4);
diff --git a/arch/x86/kernel/probe_roms.c b/arch/x86/kernel/probe_roms.c
index 319fef37d9dc..cc2c34ba7228 100644
--- a/arch/x86/kernel/probe_roms.c
+++ b/arch/x86/kernel/probe_roms.c
@@ -203,16 +203,6 @@ void __init probe_roms(void)
 	unsigned char c;
 	int i;
 
-	/*
-	 * The ROM memory range is not part of the e820 table and is therefore not
-	 * pre-validated by BIOS. The kernel page table maps the ROM region as encrypted
-	 * memory, and SNP requires encrypted memory to be validated before access.
-	 * Do that here.
-	 */
-	snp_prep_memory(video_rom_resource.start,
-			((system_rom_resource.end + 1) - video_rom_resource.start),
-			SNP_PAGE_STATE_PRIVATE);
-
 	/* video rom */
 	upper = adapter_rom_resources[0].start;
 	for (start = video_rom_resource.start; start < upper; start += 2048) {
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index ef206500ed6f..0109e6c510e0 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -9,7 +9,6 @@
 #include <linux/console.h>
 #include <linux/crash_dump.h>
 #include <linux/dma-map-ops.h>
-#include <linux/dmi.h>
 #include <linux/efi.h>
 #include <linux/ima.h>
 #include <linux/init_ohci1394_dma.h>
@@ -902,7 +901,7 @@ void __init setup_arch(char **cmdline_p)
 		efi_init();
 
 	reserve_ibft_region();
-	dmi_setup();
+	x86_init.resources.dmi_setup();
 
 	/*
 	 * VMware detection requires dmi to be available, so this
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index b59b09c2f284..7e1e63cc48e6 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -23,6 +23,7 @@
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/psp-sev.h>
+#include <linux/dmi.h>
 #include <uapi/linux/sev-guest.h>
 
 #include <asm/init.h>
@@ -795,21 +796,6 @@ void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr
 	early_set_pages_state(vaddr, paddr, npages, SNP_PAGE_STATE_SHARED);
 }
 
-void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op)
-{
-	unsigned long vaddr, npages;
-
-	vaddr = (unsigned long)__va(paddr);
-	npages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
-
-	if (op == SNP_PAGE_STATE_PRIVATE)
-		early_snp_set_memory_private(vaddr, paddr, npages);
-	else if (op == SNP_PAGE_STATE_SHARED)
-		early_snp_set_memory_shared(vaddr, paddr, npages);
-	else
-		WARN(1, "invalid memory op %d\n", op);
-}
-
 static unsigned long __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr,
 				       unsigned long vaddr_end, int op)
 {
@@ -2136,6 +2122,17 @@ void __head __noreturn snp_abort(void)
 	sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
 }
 
+/*
+ * SEV-SNP guests should only execute dmi_setup() if EFI_CONFIG_TABLES are
+ * enabled, as the alternative (fallback) logic for DMI probing in the legacy
+ * ROM region can cause a crash since this region is not pre-validated.
+ */
+void __init snp_dmi_setup(void)
+{
+	if (efi_enabled(EFI_CONFIG_TABLES))
+		dmi_setup();
+}
+
 static void dump_cpuid_table(void)
 {
 	const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index a42830dc151b..d5dc5a92635a 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -3,6 +3,7 @@
  *
  *  For licencing details see kernel-base/COPYING
  */
+#include <linux/dmi.h>
 #include <linux/init.h>
 #include <linux/ioport.h>
 #include <linux/export.h>
@@ -66,6 +67,7 @@ struct x86_init_ops x86_init __initdata = {
 		.probe_roms		= probe_roms,
 		.reserve_resources	= reserve_standard_io_resources,
 		.memory_setup		= e820__memory_setup_default,
+		.dmi_setup		= dmi_setup,
 	},
 
 	.mpparse = {