- Do not parse the confidential computing blob on non-AMD hardware as it

leads to an EFI config table ending up unmapped
 
 - Use the correct segment selector in the 32-bit version of getcpu() in
   the vDSO
 
 - Make sure vDSO and VVAR regions are placed in the 47-bit VA range even
   on 5-level paging systems
 
 - Add models 0x90-0x91 to the range of AMD Zenbleed-affected CPUs
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Merge tag 'x86_urgent_for_v6.5_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:

 - Do not parse the confidential computing blob on non-AMD hardware as
   it leads to an EFI config table ending up unmapped

 - Use the correct segment selector in the 32-bit version of getcpu() in
   the vDSO

 - Make sure vDSO and VVAR regions are placed in the 47-bit VA range
   even on 5-level paging systems

 - Add models 0x90-0x91 to the range of AMD Zenbleed-affected CPUs

* tag 'x86_urgent_for_v6.5_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu/amd: Enable Zenbleed fix for AMD Custom APU 0405
  x86/mm: Fix VDSO and VVAR placement on 5-level paging machines
  x86/linkage: Fix typo of BUILD_VDSO in asm/linkage.h
  x86/vdso: Choose the right GDT_ENTRY_CPUNODE for 32-bit getcpu() on 64-bit kernel
  x86/sev: Do not try to parse for the CC blob on non-AMD hardware

arch/x86/boot/compressed/idt_64.c

@@ -63,7 +63,14 @@ void load_stage2_idt(void)
 	set_idt_entry(X86_TRAP_PF, boot_page_fault);
 
 #ifdef CONFIG_AMD_MEM_ENCRYPT
-	set_idt_entry(X86_TRAP_VC, boot_stage2_vc);
+	/*
+	 * Clear the second stage #VC handler in case guest types
+	 * needing #VC have not been detected.
+	 */
+	if (sev_status & BIT(1))
+		set_idt_entry(X86_TRAP_VC, boot_stage2_vc);
+	else
+		set_idt_entry(X86_TRAP_VC, NULL);
 #endif
 
 	load_boot_idt(&boot_idt_desc);

arch/x86/boot/compressed/sev.c

@@ -405,10 +405,13 @@ void sev_enable(struct boot_params *bp)
 		bp->cc_blob_address = 0;
 
 	/*
-	 * Setup/preliminary detection of SNP. This will be sanity-checked
-	 * against CPUID/MSR values later.
+	 * Do an initial SEV capability check before snp_init() which
+	 * loads the CPUID page and the same checks afterwards are done
+	 * without the hypervisor and are trustworthy.
+	 *
+	 * If the HV fakes SEV support, the guest will crash'n'burn
+	 * which is good enough.
 	 */
-	snp = snp_init(bp);
 
 	/* Check for the SME/SEV support leaf */
 	eax = 0x80000000;
@@ -429,6 +432,36 @@ void sev_enable(struct boot_params *bp)
 	ecx = 0;
 	native_cpuid(&eax, &ebx, &ecx, &edx);
 	/* Check whether SEV is supported */
+	if (!(eax & BIT(1)))
+		return;
+
+	/*
+	 * Setup/preliminary detection of SNP. This will be sanity-checked
+	 * against CPUID/MSR values later.
+	 */
+	snp = snp_init(bp);
+
+	/* Now repeat the checks with the SNP CPUID table. */
+
+	/* Recheck the SME/SEV support leaf */
+	eax = 0x80000000;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	if (eax < 0x8000001f)
+		return;
+
+	/*
+	 * Recheck for the SME/SEV feature:
+	 *   CPUID Fn8000_001F[EAX]
+	 *   - Bit 0 - Secure Memory Encryption support
+	 *   - Bit 1 - Secure Encrypted Virtualization support
+	 *   CPUID Fn8000_001F[EBX]
+	 *   - Bits 5:0 - Pagetable bit position used to indicate encryption
+	 */
+	eax = 0x8000001f;
+	ecx = 0;
+	native_cpuid(&eax, &ebx, &ecx, &edx);
+	/* Check whether SEV is supported */
 	if (!(eax & BIT(1))) {
 		if (snp)
 			error("SEV-SNP support indicated by CC blob, but not CPUID.");

arch/x86/entry/vdso/vma.c

@@ -299,8 +299,8 @@ static unsigned long vdso_addr(unsigned long start, unsigned len)
 
 	/* Round the lowest possible end address up to a PMD boundary. */
 	end = (start + len + PMD_SIZE - 1) & PMD_MASK;
-	if (end >= TASK_SIZE_MAX)
-		end = TASK_SIZE_MAX;
+	if (end >= DEFAULT_MAP_WINDOW)
+		end = DEFAULT_MAP_WINDOW;
 	end -= len;
 
 	if (end > start) {

arch/x86/include/asm/linkage.h

@@ -21,7 +21,7 @@
 #define FUNCTION_PADDING
 #endif
 
-#if (CONFIG_FUNCTION_ALIGNMENT > 8) && !defined(__DISABLE_EXPORTS) && !defined(BULID_VDSO)
+#if (CONFIG_FUNCTION_ALIGNMENT > 8) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
 # define __FUNC_ALIGN		__ALIGN; FUNCTION_PADDING
 #else
 # define __FUNC_ALIGN		__ALIGN

arch/x86/include/asm/segment.h

@@ -56,7 +56,7 @@
 
 #define GDT_ENTRY_INVALID_SEG	0
 
-#ifdef CONFIG_X86_32
+#if defined(CONFIG_X86_32) && !defined(BUILD_VDSO32_64)
 /*
  * The layout of the per-CPU GDT under Linux:
  *

arch/x86/kernel/cpu/amd.c

@@ -73,6 +73,7 @@ static const int amd_erratum_1054[] =
 static const int amd_zenbleed[] =
 	AMD_LEGACY_ERRATUM(AMD_MODEL_RANGE(0x17, 0x30, 0x0, 0x4f, 0xf),
 			   AMD_MODEL_RANGE(0x17, 0x60, 0x0, 0x7f, 0xf),
+			   AMD_MODEL_RANGE(0x17, 0x90, 0x0, 0x91, 0xf),
 			   AMD_MODEL_RANGE(0x17, 0xa0, 0x0, 0xaf, 0xf));
 
 static const int amd_div0[] =