From: "tip-bot2 for Brijesh Singh" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Brijesh Singh <brijesh.singh@amd.com>,
Borislav Petkov <bp@suse.de>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: x86/sev] x86/sev: Check the VMPL level
Date: Fri, 08 Apr 2022 09:09:07 -0000 [thread overview]
Message-ID: <164940894730.389.11280397008447131834.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20220307213356.2797205-15-brijesh.singh@amd.com>
The following commit has been merged into the x86/sev branch of tip:
Commit-ID: 81cc3df9a90e7817494421ecc48ede6bd5e8132b
Gitweb: https://git.kernel.org/tip/81cc3df9a90e7817494421ecc48ede6bd5e8132b
Author: Brijesh Singh <brijesh.singh@amd.com>
AuthorDate: Wed, 09 Feb 2022 12:10:08 -06:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 06 Apr 2022 13:10:34 +02:00
x86/sev: Check the VMPL level
The Virtual Machine Privilege Level (VMPL) feature in the SEV-SNP
architecture allows a guest VM to divide its address space into four
levels. The level can be used to provide hardware isolated abstraction
layers within a VM. VMPL0 is the highest privilege level, and VMPL3 is
the least privilege level. Certain operations must be done by the VMPL0
software, such as:
* Validate or invalidate memory range (PVALIDATE instruction)
* Allocate VMSA page (RMPADJUST instruction when VMSA=1)
The initial SNP support requires that the guest kernel is running at
VMPL0. Add such a check to verify the guest is running at level 0 before
continuing the boot. There is no easy method to query the current VMPL
level, so use the RMPADJUST instruction to determine whether the guest
is running at the VMPL0.
[ bp: Massage commit message. ]
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220307213356.2797205-15-brijesh.singh@amd.com
---
arch/x86/boot/compressed/sev.c | 28 ++++++++++++++++++++++++++--
arch/x86/include/asm/sev-common.h | 1 +
arch/x86/include/asm/sev.h | 16 ++++++++++++++++
3 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 5b38931..eb42178 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -199,6 +199,26 @@ finish:
sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
}
+static void enforce_vmpl0(void)
+{
+ u64 attrs;
+ int err;
+
+ /*
+ * RMPADJUST modifies RMP permissions of a lesser-privileged (numerically
+ * higher) privilege level. Here, clear the VMPL1 permission mask of the
+ * GHCB page. If the guest is not running at VMPL0, this will fail.
+ *
+ * If the guest is running at VMPL0, it will succeed. Even if that operation
+ * modifies permission bits, it is still ok to do so currently because Linux
+ * SNP guests are supported only on VMPL0 so VMPL1 or higher permission masks
+ * changing is a don't-care.
+ */
+ attrs = 1;
+ if (rmpadjust((unsigned long)&boot_ghcb_page, RMP_PG_SIZE_4K, attrs))
+ sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_NOT_VMPL0);
+}
+
void sev_enable(struct boot_params *bp)
{
unsigned int eax, ebx, ecx, edx;
@@ -242,8 +262,12 @@ void sev_enable(struct boot_params *bp)
* SNP is supported in v2 of the GHCB spec which mandates support for HV
* features.
*/
- if (sev_status & MSR_AMD64_SEV_SNP_ENABLED && !(get_hv_features() & GHCB_HV_FT_SNP))
- sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+ if (sev_status & MSR_AMD64_SEV_SNP_ENABLED) {
+ if (!(get_hv_features() & GHCB_HV_FT_SNP))
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
+ enforce_vmpl0();
+ }
sme_me_mask = BIT_ULL(ebx & 0x3f);
}
diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
index 6f037c2..7ac5842 100644
--- a/arch/x86/include/asm/sev-common.h
+++ b/arch/x86/include/asm/sev-common.h
@@ -89,6 +89,7 @@
#define GHCB_TERM_REGISTER 0 /* GHCB GPA registration failure */
#define GHCB_TERM_PSC 1 /* Page State Change failure */
#define GHCB_TERM_PVALIDATE 2 /* Pvalidate failure */
+#define GHCB_TERM_NOT_VMPL0 3 /* SNP guest is not running at VMPL-0 */
#define GHCB_RESP_CODE(v) ((v) & GHCB_MSR_INFO_MASK)
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 4ee9897..e374518 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -63,6 +63,9 @@ extern bool handle_vc_boot_ghcb(struct pt_regs *regs);
/* Software defined (when rFlags.CF = 1) */
#define PVALIDATE_FAIL_NOUPDATE 255
+/* RMP page size */
+#define RMP_PG_SIZE_4K 0
+
#ifdef CONFIG_AMD_MEM_ENCRYPT
extern struct static_key_false sev_es_enable_key;
extern void __sev_es_ist_enter(struct pt_regs *regs);
@@ -90,6 +93,18 @@ extern enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
struct es_em_ctxt *ctxt,
u64 exit_code, u64 exit_info_1,
u64 exit_info_2);
+static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs)
+{
+ int rc;
+
+ /* "rmpadjust" mnemonic support in binutils 2.36 and newer */
+ asm volatile(".byte 0xF3,0x0F,0x01,0xFE\n\t"
+ : "=a"(rc)
+ : "a"(vaddr), "c"(rmp_psize), "d"(attrs)
+ : "memory", "cc");
+
+ return rc;
+}
static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
{
bool no_rmpupdate;
@@ -114,6 +129,7 @@ static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { ret
static inline void sev_es_nmi_complete(void) { }
static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate) { return 0; }
+static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs) { return 0; }
#endif
#endif
next prev parent reply other threads:[~2022-04-08 9:13 UTC|newest]
Thread overview: 129+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-07 21:33 [PATCH v12 00/46] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 01/46] KVM: SVM: Define sev_features and vmpl field in the VMSA Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] KVM: SVM: Define sev_features and VMPL " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 02/46] KVM: SVM: Create a separate mapping for the SEV-ES save area Brijesh Singh
2022-04-05 18:27 ` [PATCH v12 2.1/46] " Brijesh Singh
2022-04-05 18:55 ` Borislav Petkov
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Tom Lendacky
2022-03-07 21:33 ` [PATCH v12 03/46] KVM: SVM: Create a separate mapping for the GHCB " Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Tom Lendacky
2022-03-07 21:33 ` [PATCH v12 04/46] KVM: SVM: Update the SEV-ES save area mapping Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Tom Lendacky
2022-03-07 21:33 ` [PATCH v12 05/46] x86/boot: Introduce helpers for MSR reads/writes Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 06/46] x86/boot: Use MSR read/write helpers instead of inline assembly Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 07/46] x86/compressed/64: Detect/setup SEV/SME features earlier in boot Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] x86/compressed/64: Detect/setup SEV/SME features earlier during boot tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 08/46] x86/sev: Detect/setup SEV/SME features earlier in boot Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 09/46] x86/mm: Extend cc_attr to include AMD SEV-SNP Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 10/46] x86/sev: Define the Linux specific guest termination reasons Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] x86/sev: Define the Linux-specific " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 11/46] x86/sev: Save the negotiated GHCB version Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 12/46] x86/sev: Check SEV-SNP features support Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 13/46] x86/sev: Add a helper for the PVALIDATE instruction Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 14/46] x86/sev: Check the vmpl level Brijesh Singh
2022-04-08 9:09 ` tip-bot2 for Brijesh Singh [this message]
2022-03-07 21:33 ` [PATCH v12 15/46] x86/compressed: Add helper for validating pages in the decompression stage Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 16/46] x86/compressed: Register GHCB memory when SEV-SNP is active Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 17/46] x86/sev: " Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 18/46] x86/sev: Add helper for validating pages in early enc attribute changes Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 19/46] x86/kernel: Make the .bss..decrypted section shared in RMP table Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] x86/kernel: Mark the .bss..decrypted section as shared in the " tip-bot2 for Brijesh Singh
2022-06-14 0:46 ` [PATCH v12 19/46] x86/kernel: Make the .bss..decrypted section shared in " Sean Christopherson
2022-06-14 15:43 ` Sean Christopherson
2022-06-14 16:01 ` Tom Lendacky
2022-06-14 16:13 ` Sean Christopherson
2022-06-14 19:00 ` Tom Lendacky
2022-06-14 19:52 ` Sean Christopherson
2022-06-16 16:17 ` Tom Lendacky
2022-06-16 16:41 ` Sean Christopherson
2022-07-01 16:51 ` Borislav Petkov
2022-07-07 20:43 ` Sean Christopherson
2022-03-07 21:33 ` [PATCH v12 20/46] x86/kernel: Validate ROM memory before accessing when SEV-SNP is active Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 21/46] x86/mm: Validate memory when changing the C-bit Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 22/46] x86/sev: Use SEV-SNP AP creation to start secondary CPUs Brijesh Singh
2022-04-05 0:24 ` Sean Christopherson
2022-04-05 16:20 ` Brijesh Singh
2022-04-05 19:41 ` Sean Christopherson
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Tom Lendacky
2022-03-07 21:33 ` [PATCH v12 23/46] x86/head/64: Re-enable stack protection Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 24/46] x86/compressed/acpi: Move EFI detection to helper Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 25/46] x86/compressed/acpi: Move EFI system table lookup " Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 26/46] x86/compressed/acpi: Move EFI config " Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 27/46] x86/compressed/acpi: Move EFI vendor " Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 28/46] x86/compressed/acpi: Move EFI kexec handling into common code Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 29/46] x86/boot: Add Confidential Computing type to setup_data Brijesh Singh
2022-04-06 21:19 ` Thomas Gleixner
2022-04-07 14:47 ` Borislav Petkov
2022-04-07 14:57 ` Brijesh Singh
2022-07-17 5:08 ` H. Peter Anvin
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 30/46] KVM: x86: Move lookup of indexed CPUID leafs to helper Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 31/46] x86/sev: Move MSR-based VMGEXITs for CPUID " Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 32/46] x86/compressed/64: Add support for SEV-SNP CPUID table in #VC handlers Brijesh Singh
2022-03-10 14:51 ` Peter Gonda
2022-03-10 21:25 ` Michael Roth
2022-03-11 17:06 ` Joerg Roedel
2022-03-14 17:34 ` Peter Gonda
2022-03-17 13:11 ` Boris Petkov
2022-03-17 20:20 ` Peter Gonda
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 33/46] x86/boot: Add a pointer to Confidential Computing blob in bootparams Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 34/46] x86/compressed: Add SEV-SNP feature detection/setup Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 35/46] x86/compressed: Use firmware-validated CPUID leaves for SEV-SNP guests Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 36/46] x86/compressed: Export and rename add_identity_map() Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 37/46] x86/compressed/64: Add identity mapping for Confidential Computing blob Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 38/46] x86/sev: Add SEV-SNP feature detection/setup Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 39/46] x86/sev: Use firmware-validated CPUID for SEV-SNP guests Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 40/46] x86/sev: add sev=debug cmdline option to dump SNP CPUID table Brijesh Singh
2022-03-25 9:24 ` Borislav Petkov
2022-04-08 9:08 ` [tip: x86/sev] x86/sev: Add a sev= cmdline option tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 41/46] x86/sev: Provide support for SNP guest request NAEs Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 42/46] x86/sev: Register SEV-SNP guest request platform device Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 43/46] virt: Add SEV-SNP guest driver Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-04-18 16:42 ` Dionna Amalie Glaze
2022-04-18 17:14 ` Borislav Petkov
2022-04-18 17:40 ` Tom Lendacky
2022-04-18 21:18 ` Borislav Petkov
2022-08-24 18:01 ` [PATCH v12 43/46] " Dionna Amalie Glaze
2022-08-24 19:28 ` Peter Gonda
2022-08-25 18:54 ` Tom Lendacky
2022-08-25 20:09 ` Peter Gonda
2022-03-07 21:33 ` [PATCH v12 44/46] virt: sevguest: Add support to derive key Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 45/46] virt: sevguest: Add support to get extended report Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 46/46] virt: sevguest: Add documentation for SEV-SNP CPUID Enforcement Brijesh Singh
2022-03-14 15:37 ` Peter Gonda
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:53 ` [PATCH v12 43.1/46] virt: Add SEV-SNP guest driver Brijesh Singh
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