Merge tag 'x86_sev_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 SEV updates from Borislav Petkov:

 - Add the x86 part of the SEV-SNP host support.

   This will allow the kernel to be used as a KVM hypervisor capable of
   running SNP (Secure Nested Paging) guests. Roughly speaking, SEV-SNP
   is the ultimate goal of the AMD confidential computing side,
   providing the most comprehensive confidential computing environment
   up to date.

   This is the x86 part and there is a KVM part which did not get ready
   in time for the merge window so latter will be forthcoming in the
   next cycle.

 - Rework the early code's position-dependent SEV variable references in
   order to allow building the kernel with clang and -fPIE/-fPIC and
   -mcmodel=kernel

 - The usual set of fixes, cleanups and improvements all over the place

* tag 'x86_sev_for_v6.9_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  x86/sev: Disable KMSAN for memory encryption TUs
  x86/sev: Dump SEV_STATUS
  crypto: ccp - Have it depend on AMD_IOMMU
  iommu/amd: Fix failure return from snp_lookup_rmpentry()
  x86/sev: Fix position dependent variable references in startup code
  crypto: ccp: Make snp_range_list static
  x86/Kconfig: Remove CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
  Documentation: virt: Fix up pre-formatted text block for SEV ioctls
  crypto: ccp: Add the SNP_SET_CONFIG command
  crypto: ccp: Add the SNP_COMMIT command
  crypto: ccp: Add the SNP_PLATFORM_STATUS command
  x86/cpufeatures: Enable/unmask SEV-SNP CPU feature
  KVM: SEV: Make AVIC backing, VMSA and VMCB memory allocation SNP safe
  crypto: ccp: Add panic notifier for SEV/SNP firmware shutdown on kdump
  iommu/amd: Clean up RMP entries for IOMMU pages during SNP shutdown
  crypto: ccp: Handle legacy SEV commands when SNP is enabled
  crypto: ccp: Handle non-volatile INIT_EX data when SNP is enabled
  crypto: ccp: Handle the legacy TMR allocation when SNP is enabled
  x86/sev: Introduce an SNP leaked pages list
  crypto: ccp: Provide an API to issue SEV and SNP commands
  ...

Author: torvalds

Documentation/admin-guide/kernel-parameters.txt

@@ -3318,9 +3318,7 @@
 
 	mem_encrypt=	[X86-64] AMD Secure Memory Encryption (SME) control
 			Valid arguments: on, off
-			Default (depends on kernel configuration option):
-			  on  (CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=y)
-			  off (CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=n)
+			Default: off
 			mem_encrypt=on:		Activate SME
 			mem_encrypt=off:	Do not activate SME
 

Documentation/arch/x86/amd-memory-encryption.rst

@@ -87,14 +87,14 @@ The state of SME in the Linux kernel can be documented as follows:
 	  kernel is non-zero).
 
 SME can also be enabled and activated in the BIOS. If SME is enabled and
-activated in the BIOS, then all memory accesses will be encrypted and it will
-not be necessary to activate the Linux memory encryption support.  If the BIOS
-merely enables SME (sets bit 23 of the MSR_AMD64_SYSCFG), then Linux can activate
-memory encryption by default (CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=y) or
-by supplying mem_encrypt=on on the kernel command line.  However, if BIOS does
-not enable SME, then Linux will not be able to activate memory encryption, even
-if configured to do so by default or the mem_encrypt=on command line parameter
-is specified.
+activated in the BIOS, then all memory accesses will be encrypted and it
+will not be necessary to activate the Linux memory encryption support.
+
+If the BIOS merely enables SME (sets bit 23 of the MSR_AMD64_SYSCFG),
+then memory encryption can be enabled by supplying mem_encrypt=on on the
+kernel command line.  However, if BIOS does not enable SME, then Linux
+will not be able to activate memory encryption, even if configured to do
+so by default or the mem_encrypt=on command line parameter is specified.
 
 Secure Nested Paging (SNP)
 ==========================

Documentation/virt/coco/sev-guest.rst

@@ -67,6 +67,23 @@ counter (e.g. counter overflow), then -EIO will be returned.
                 };
         };
 
+The host ioctls are issued to a file descriptor of the /dev/sev device.
+The ioctl accepts the command ID/input structure documented below.
+
+::
+
+        struct sev_issue_cmd {
+                /* Command ID */
+                __u32 cmd;
+
+                /* Command request structure */
+                __u64 data;
+
+                /* Firmware error code on failure (see psp-sev.h) */
+                __u32 error;
+        };
+
+
 2.1 SNP_GET_REPORT
 ------------------
 
@@ -124,6 +141,41 @@ be updated with the expected value.
 
 See GHCB specification for further detail on how to parse the certificate blob.
 
+2.4 SNP_PLATFORM_STATUS
+-----------------------
+:Technology: sev-snp
+:Type: hypervisor ioctl cmd
+:Parameters (out): struct sev_user_data_snp_status
+:Returns (out): 0 on success, -negative on error
+
+The SNP_PLATFORM_STATUS command is used to query the SNP platform status. The
+status includes API major, minor version and more. See the SEV-SNP
+specification for further details.
+
+2.5 SNP_COMMIT
+--------------
+:Technology: sev-snp
+:Type: hypervisor ioctl cmd
+:Returns (out): 0 on success, -negative on error
+
+SNP_COMMIT is used to commit the currently installed firmware using the
+SEV-SNP firmware SNP_COMMIT command. This prevents roll-back to a previously
+committed firmware version. This will also update the reported TCB to match
+that of the currently installed firmware.
+
+2.6 SNP_SET_CONFIG
+------------------
+:Technology: sev-snp
+:Type: hypervisor ioctl cmd
+:Parameters (in): struct sev_user_data_snp_config
+:Returns (out): 0 on success, -negative on error
+
+SNP_SET_CONFIG is used to set the system-wide configuration such as
+reported TCB version in the attestation report. The command is similar
+to SNP_CONFIG command defined in the SEV-SNP spec. The current values of
+the firmware parameters affected by this command can be queried via
+SNP_PLATFORM_STATUS.
+
 3. SEV-SNP CPUID Enforcement
 ============================
 

arch/x86/Kbuild

@@ -28,5 +28,7 @@ obj-y += net/
 
 obj-$(CONFIG_KEXEC_FILE) += purgatory/
 
+obj-y += virt/svm/
+
 # for cleaning
 subdir- += boot tools

arch/x86/Kconfig

@@ -1548,19 +1548,6 @@ config AMD_MEM_ENCRYPT
 	  This requires an AMD processor that supports Secure Memory
 	  Encryption (SME).
 
-config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
-	bool "Activate AMD Secure Memory Encryption (SME) by default"
-	depends on AMD_MEM_ENCRYPT
-	help
-	  Say yes to have system memory encrypted by default if running on
-	  an AMD processor that supports Secure Memory Encryption (SME).
-
-	  If set to Y, then the encryption of system memory can be
-	  deactivated with the mem_encrypt=off command line option.
-
-	  If set to N, then the encryption of system memory can be
-	  activated with the mem_encrypt=on command line option.
-
 # Common NUMA Features
 config NUMA
 	bool "NUMA Memory Allocation and Scheduler Support"

arch/x86/boot/compressed/sev.c

@@ -304,6 +304,10 @@ void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code)
 	if (result != ES_OK)
 		goto finish;
 
+	result = vc_check_opcode_bytes(&ctxt, exit_code);
+	if (result != ES_OK)
+		goto finish;
+
 	switch (exit_code) {
 	case SVM_EXIT_RDTSC:
 	case SVM_EXIT_RDTSCP:
@@ -365,7 +369,7 @@ static void enforce_vmpl0(void)
 				 MSR_AMD64_SNP_VMPL_SSS |		\
 				 MSR_AMD64_SNP_SECURE_TSC |		\
 				 MSR_AMD64_SNP_VMGEXIT_PARAM |		\
-				 MSR_AMD64_SNP_VMSA_REG_PROTECTION |	\
+				 MSR_AMD64_SNP_VMSA_REG_PROT |		\
 				 MSR_AMD64_SNP_RESERVED_BIT13 |		\
 				 MSR_AMD64_SNP_RESERVED_BIT15 |		\
 				 MSR_AMD64_SNP_RESERVED_MASK)

arch/x86/coco/core.c

@@ -14,7 +14,7 @@
 #include <asm/processor.h>
 
 enum cc_vendor cc_vendor __ro_after_init = CC_VENDOR_NONE;
-static u64 cc_mask __ro_after_init;
+u64 cc_mask __ro_after_init;
 
 static bool noinstr intel_cc_platform_has(enum cc_attr attr)
 {
@@ -148,8 +148,3 @@ u64 cc_mkdec(u64 val)
 	}
 }
 EXPORT_SYMBOL_GPL(cc_mkdec);
-
-__init void cc_set_mask(u64 mask)
-{
-	cc_mask = mask;
-}

arch/x86/include/asm/asm.h

@@ -113,6 +113,20 @@
 
 #endif
 
+#ifndef __ASSEMBLY__
+#ifndef __pic__
+static __always_inline __pure void *rip_rel_ptr(void *p)
+{
+	asm("leaq %c1(%%rip), %0" : "=r"(p) : "i"(p));
+
+	return p;
+}
+#define RIP_REL_REF(var)	(*(typeof(&(var)))rip_rel_ptr(&(var)))
+#else
+#define RIP_REL_REF(var)	(var)
+#endif
+#endif
+
 /*
  * Macros to generate condition code outputs from inline assembly,
  * The output operand must be type "bool".

arch/x86/include/asm/coco.h

@@ -2,6 +2,7 @@
 #ifndef _ASM_X86_COCO_H
 #define _ASM_X86_COCO_H
 
+#include <asm/asm.h>
 #include <asm/types.h>
 
 enum cc_vendor {
@@ -12,7 +13,13 @@ enum cc_vendor {
 
 #ifdef CONFIG_ARCH_HAS_CC_PLATFORM
 extern enum cc_vendor cc_vendor;
-void cc_set_mask(u64 mask);
+extern u64 cc_mask;
+
+static inline void cc_set_mask(u64 mask)
+{
+	RIP_REL_REF(cc_mask) = mask;
+}
+
 u64 cc_mkenc(u64 val);
 u64 cc_mkdec(u64 val);
 #else

arch/x86/include/asm/cpufeatures.h

@@ -442,6 +442,7 @@
 #define X86_FEATURE_SEV			(19*32+ 1) /* AMD Secure Encrypted Virtualization */
 #define X86_FEATURE_VM_PAGE_FLUSH	(19*32+ 2) /* "" VM Page Flush MSR is supported */
 #define X86_FEATURE_SEV_ES		(19*32+ 3) /* AMD Secure Encrypted Virtualization - Encrypted State */
+#define X86_FEATURE_SEV_SNP		(19*32+ 4) /* AMD Secure Encrypted Virtualization - Secure Nested Paging */
 #define X86_FEATURE_V_TSC_AUX		(19*32+ 9) /* "" Virtual TSC_AUX */
 #define X86_FEATURE_SME_COHERENT	(19*32+10) /* "" AMD hardware-enforced cache coherency */
 #define X86_FEATURE_DEBUG_SWAP		(19*32+14) /* AMD SEV-ES full debug state swap support */