From: Brijesh Singh <brijesh.singh@amd.com>
To: <x86@kernel.org>, <linux-kernel@vger.kernel.org>,
<kvm@vger.kernel.org>, <linux-efi@vger.kernel.org>,
<platform-driver-x86@vger.kernel.org>,
<linux-coco@lists.linux.dev>, <linux-mm@kvack.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Joerg Roedel <jroedel@suse.de>,
Tom Lendacky <thomas.lendacky@amd.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Ard Biesheuvel <ardb@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
"Vitaly Kuznetsov" <vkuznets@redhat.com>,
Jim Mattson <jmattson@google.com>,
"Andy Lutomirski" <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Sergio Lopez <slp@redhat.com>, Peter Gonda <pgonda@google.com>,
"Peter Zijlstra" <peterz@infradead.org>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
David Rientjes <rientjes@google.com>,
Dov Murik <dovmurik@linux.ibm.com>,
Tobin Feldman-Fitzthum <tobin@ibm.com>,
Borislav Petkov <bp@alien8.de>,
Michael Roth <michael.roth@amd.com>,
Vlastimil Babka <vbabka@suse.cz>,
"Kirill A . Shutemov" <kirill@shutemov.name>,
Andi Kleen <ak@linux.intel.com>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
<brijesh.ksingh@gmail.com>, <tony.luck@intel.com>,
<marcorr@google.com>,
<sathyanarayanan.kuppuswamy@linux.intel.com>,
Brijesh Singh <brijesh.singh@amd.com>
Subject: [PATCH v9 37/43] x86/sev: Add SEV-SNP feature detection/setup
Date: Fri, 28 Jan 2022 11:17:58 -0600 [thread overview]
Message-ID: <20220128171804.569796-38-brijesh.singh@amd.com> (raw)
In-Reply-To: <20220128171804.569796-1-brijesh.singh@amd.com>
From: Michael Roth <michael.roth@amd.com>
Initial/preliminary detection of SEV-SNP is done via the Confidential
Computing blob. Check for it prior to the normal SEV/SME feature
initialization, and add some sanity checks to confirm it agrees with
SEV-SNP CPUID/MSR bits.
Signed-off-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
arch/x86/boot/compressed/sev.c | 33 ---------------
arch/x86/include/asm/sev.h | 2 +
arch/x86/kernel/sev-shared.c | 33 +++++++++++++++
arch/x86/kernel/sev.c | 64 ++++++++++++++++++++++++++++++
arch/x86/mm/mem_encrypt_identity.c | 8 ++++
5 files changed, 107 insertions(+), 33 deletions(-)
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index faf432684870..cde5658e1007 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -364,39 +364,6 @@ static struct cc_blob_sev_info *snp_find_cc_blob_efi(struct boot_params *bp)
EFI_CC_BLOB_GUID);
}
-struct cc_setup_data {
- struct setup_data header;
- u32 cc_blob_address;
-};
-
-static struct cc_setup_data *get_cc_setup_data(struct boot_params *bp)
-{
- struct setup_data *hdr = (struct setup_data *)bp->hdr.setup_data;
-
- while (hdr) {
- if (hdr->type == SETUP_CC_BLOB)
- return (struct cc_setup_data *)hdr;
- hdr = (struct setup_data *)hdr->next;
- }
-
- return NULL;
-}
-
-/*
- * Search for a Confidential Computing blob passed in as a setup_data entry
- * via the Linux Boot Protocol.
- */
-static struct cc_blob_sev_info *snp_find_cc_blob_setup_data(struct boot_params *bp)
-{
- struct cc_setup_data *sd;
-
- sd = get_cc_setup_data(bp);
- if (!sd)
- return NULL;
-
- return (struct cc_blob_sev_info *)(unsigned long)sd->cc_blob_address;
-}
-
/*
* Initial set up of SEV-SNP relies on information provided by the
* Confidential Computing blob, which can be passed to the boot kernel
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 4e3909042001..219abb4590f2 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -153,6 +153,7 @@ void snp_set_memory_shared(unsigned long vaddr, unsigned int npages);
void snp_set_memory_private(unsigned long vaddr, unsigned int npages);
void snp_set_wakeup_secondary_cpu(void);
bool snp_init(struct boot_params *bp);
+void snp_abort(void);
#else
static inline void sev_es_ist_enter(struct pt_regs *regs) { }
static inline void sev_es_ist_exit(void) { }
@@ -171,6 +172,7 @@ static inline void snp_set_memory_shared(unsigned long vaddr, unsigned int npage
static inline void snp_set_memory_private(unsigned long vaddr, unsigned int npages) { }
static inline void snp_set_wakeup_secondary_cpu(void) { }
static inline bool snp_init(struct boot_params *bp) { return false; }
+static inline void snp_abort(void) { }
#endif
#endif
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index dea9f7b28620..2bddbfea079b 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -928,3 +928,36 @@ static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,
return ES_OK;
}
+
+struct cc_setup_data {
+ struct setup_data header;
+ u32 cc_blob_address;
+};
+
+static struct cc_setup_data *get_cc_setup_data(struct boot_params *bp)
+{
+ struct setup_data *hdr = (struct setup_data *)bp->hdr.setup_data;
+
+ while (hdr) {
+ if (hdr->type == SETUP_CC_BLOB)
+ return (struct cc_setup_data *)hdr;
+ hdr = (struct setup_data *)hdr->next;
+ }
+
+ return NULL;
+}
+
+/*
+ * Search for a Confidential Computing blob passed in as a setup_data entry
+ * via the Linux Boot Protocol.
+ */
+static struct cc_blob_sev_info *snp_find_cc_blob_setup_data(struct boot_params *bp)
+{
+ struct cc_setup_data *sd;
+
+ sd = get_cc_setup_data(bp);
+ if (!sd)
+ return NULL;
+
+ return (struct cc_blob_sev_info *)(unsigned long)sd->cc_blob_address;
+}
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index c2bc07eb97e9..5c72b21c7e7b 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -1983,3 +1983,67 @@ bool __init handle_vc_boot_ghcb(struct pt_regs *regs)
while (true)
halt();
}
+
+/*
+ * Initial set up of SEV-SNP relies on information provided by the
+ * Confidential Computing blob, which can be passed to the kernel
+ * in the following ways, depending on how it is booted:
+ *
+ * - when booted via the boot/decompress kernel:
+ * - via boot_params
+ *
+ * - when booted directly by firmware/bootloader (e.g. CONFIG_PVH):
+ * - via a setup_data entry, as defined by the Linux Boot Protocol
+ *
+ * Scan for the blob in that order.
+ */
+static __init struct cc_blob_sev_info *snp_find_cc_blob(struct boot_params *bp)
+{
+ struct cc_blob_sev_info *cc_info;
+
+ /* Boot kernel would have passed the CC blob via boot_params. */
+ if (bp->cc_blob_address) {
+ cc_info = (struct cc_blob_sev_info *)(unsigned long)bp->cc_blob_address;
+ goto found_cc_info;
+ }
+
+ /*
+ * If kernel was booted directly, without the use of the
+ * boot/decompression kernel, the CC blob may have been passed via
+ * setup_data instead.
+ */
+ cc_info = snp_find_cc_blob_setup_data(bp);
+ if (!cc_info)
+ return NULL;
+
+found_cc_info:
+ if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC)
+ snp_abort();
+
+ return cc_info;
+}
+
+bool __init snp_init(struct boot_params *bp)
+{
+ struct cc_blob_sev_info *cc_info;
+
+ if (!bp)
+ return false;
+
+ cc_info = snp_find_cc_blob(bp);
+ if (!cc_info)
+ return false;
+
+ /*
+ * The CC blob will be used later to access the secrets page. Cache
+ * it here like the boot kernel does.
+ */
+ bp->cc_blob_address = (u32)(unsigned long)cc_info;
+
+ return true;
+}
+
+void __init snp_abort(void)
+{
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+}
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index 3f0abb403340..2f723e106ed3 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -44,6 +44,7 @@
#include <asm/setup.h>
#include <asm/sections.h>
#include <asm/cmdline.h>
+#include <asm/sev.h>
#include "mm_internal.h"
@@ -508,8 +509,11 @@ void __init sme_enable(struct boot_params *bp)
bool active_by_default;
unsigned long me_mask;
char buffer[16];
+ bool snp;
u64 msr;
+ snp = snp_init(bp);
+
/* Check for the SME/SEV support leaf */
eax = 0x80000000;
ecx = 0;
@@ -541,6 +545,10 @@ void __init sme_enable(struct boot_params *bp)
sev_status = __rdmsr(MSR_AMD64_SEV);
feature_mask = (sev_status & MSR_AMD64_SEV_ENABLED) ? AMD_SEV_BIT : AMD_SME_BIT;
+ /* The SEV-SNP CC blob should never be present unless SEV-SNP is enabled. */
+ if (snp && !(sev_status & MSR_AMD64_SEV_SNP_ENABLED))
+ snp_abort();
+
/* Check if memory encryption is enabled */
if (feature_mask == AMD_SME_BIT) {
/*
--
2.25.1
next prev parent reply other threads:[~2022-01-28 17:21 UTC|newest]
Thread overview: 114+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-28 17:17 [PATCH v9 00/43] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 01/43] KVM: SVM: Define sev_features and vmpl field in the VMSA Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 02/43] KVM: SVM: Create a separate mapping for the SEV-ES save area Brijesh Singh
2022-02-01 13:02 ` Borislav Petkov
2022-02-09 15:02 ` Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 03/43] KVM: SVM: Create a separate mapping for the GHCB " Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 04/43] KVM: SVM: Update the SEV-ES save area mapping Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 05/43] x86/compressed/64: Detect/setup SEV/SME features earlier in boot Brijesh Singh
2022-02-01 18:08 ` Borislav Petkov
2022-02-01 20:35 ` Michael Roth
2022-02-01 21:28 ` Borislav Petkov
2022-02-02 0:52 ` Michael Roth
2022-02-02 6:09 ` Borislav Petkov
2022-02-02 17:28 ` Michael Roth
2022-02-02 18:57 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 06/43] x86/sev: " Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 07/43] x86/mm: Extend cc_attr to include AMD SEV-SNP Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 08/43] x86/sev: Define the Linux specific guest termination reasons Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 09/43] x86/sev: Save the negotiated GHCB version Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 10/43] x86/sev: Check SEV-SNP features support Brijesh Singh
2022-02-01 19:59 ` Borislav Petkov
2022-02-02 14:28 ` Brijesh Singh
2022-02-02 15:37 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 11/43] x86/sev: Add a helper for the PVALIDATE instruction Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 12/43] x86/sev: Check the vmpl level Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 13/43] x86/compressed: Add helper for validating pages in the decompression stage Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 14/43] x86/compressed: Register GHCB memory when SEV-SNP is active Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 15/43] x86/sev: " Brijesh Singh
2022-02-02 10:34 ` Borislav Petkov
2022-02-02 14:29 ` Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 16/43] x86/sev: Add helper for validating pages in early enc attribute changes Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 17/43] x86/kernel: Make the .bss..decrypted section shared in RMP table Brijesh Singh
2022-02-02 11:06 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 18/43] x86/kernel: Validate ROM memory before accessing when SEV-SNP is active Brijesh Singh
2022-02-02 15:41 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 19/43] x86/mm: Add support to validate memory when changing C-bit Brijesh Singh
2022-02-02 16:10 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 20/43] x86/sev: Use SEV-SNP AP creation to start secondary CPUs Brijesh Singh
2022-02-03 6:50 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 21/43] x86/head/64: Re-enable stack protection Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 22/43] x86/sev: Move MSR-based VMGEXITs for CPUID to helper Brijesh Singh
2022-02-03 13:59 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 23/43] KVM: x86: Move lookup of indexed CPUID leafs " Brijesh Singh
2022-02-03 15:16 ` Borislav Petkov
2022-02-03 16:44 ` Michael Roth
2022-02-05 12:58 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 24/43] x86/compressed/acpi: Move EFI detection " Brijesh Singh
2022-02-03 14:39 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 25/43] x86/compressed/acpi: Move EFI system table lookup " Brijesh Singh
2022-02-03 14:48 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 26/43] x86/compressed/acpi: Move EFI config " Brijesh Singh
2022-02-03 15:13 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 27/43] x86/compressed/acpi: Move EFI vendor " Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 28/43] x86/compressed/acpi: Move EFI kexec handling into common code Brijesh Singh
2022-02-04 16:09 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 29/43] x86/boot: Add Confidential Computing type to setup_data Brijesh Singh
2022-02-04 16:21 ` Borislav Petkov
2022-02-04 17:41 ` Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 30/43] KVM: SEV: Add documentation for SEV-SNP CPUID Enforcement Brijesh Singh
2022-02-07 23:48 ` Sean Christopherson
2022-02-08 14:54 ` Michael Roth
2022-02-08 15:11 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 31/43] x86/compressed/64: Add support for SEV-SNP CPUID table in #VC handlers Brijesh Singh
2022-02-05 10:54 ` Borislav Petkov
2022-02-05 15:42 ` Michael Roth
2022-02-05 16:22 ` Michael Roth
2022-02-06 13:37 ` Borislav Petkov
2022-02-07 15:37 ` Michael Roth
2022-02-07 17:52 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 32/43] x86/boot: Add a pointer to Confidential Computing blob in bootparams Brijesh Singh
2022-02-05 13:07 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 33/43] x86/compressed: Add SEV-SNP feature detection/setup Brijesh Singh
2022-02-06 16:41 ` Borislav Petkov
2022-02-08 13:50 ` Michael Roth
2022-02-08 15:02 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 34/43] x86/compressed: Use firmware-validated CPUID leaves for SEV-SNP guests Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 35/43] x86/compressed: Export and rename add_identity_map() Brijesh Singh
2022-02-06 19:01 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 36/43] x86/compressed/64: Add identity mapping for Confidential Computing blob Brijesh Singh
2022-02-06 19:21 ` Borislav Petkov
2022-01-28 17:17 ` Brijesh Singh [this message]
2022-02-06 19:38 ` [PATCH v9 37/43] x86/sev: Add SEV-SNP feature detection/setup Borislav Petkov
2022-02-08 5:25 ` Michael Roth
2022-01-28 17:17 ` [PATCH v9 38/43] x86/sev: Use firmware-validated CPUID for SEV-SNP guests Brijesh Singh
2022-02-05 17:19 ` Michael Roth
2022-02-06 15:46 ` Borislav Petkov
2022-02-07 17:00 ` Michael Roth
2022-02-07 18:43 ` Borislav Petkov
2022-02-06 19:50 ` Borislav Petkov
2022-01-28 17:18 ` [PATCH v9 39/43] x86/sev: Provide support for SNP guest request NAEs Brijesh Singh
2022-02-01 20:17 ` Peter Gonda
2022-01-28 17:18 ` [PATCH v9 40/43] x86/sev: Register SEV-SNP guest request platform device Brijesh Singh
2022-02-01 20:21 ` Peter Gonda
2022-02-02 16:27 ` Brijesh Singh
2022-02-06 20:05 ` Borislav Petkov
2022-01-28 17:18 ` [PATCH v9 41/43] virt: Add SEV-SNP guest driver Brijesh Singh
2022-02-01 20:33 ` Peter Gonda
2022-02-06 22:39 ` Borislav Petkov
2022-02-07 14:41 ` Brijesh Singh
2022-02-07 15:22 ` Borislav Petkov
2022-01-28 17:18 ` [PATCH v9 42/43] virt: sevguest: Add support to derive key Brijesh Singh
2022-02-01 20:39 ` Peter Gonda
2022-02-02 22:31 ` Brijesh Singh
2022-02-07 8:52 ` Borislav Petkov
2022-02-07 16:23 ` Brijesh Singh
2022-02-07 19:09 ` Dov Murik
2022-02-07 20:08 ` Brijesh Singh
2022-02-07 20:28 ` Borislav Petkov
2022-02-08 7:56 ` Dov Murik
2022-02-08 10:51 ` Borislav Petkov
2022-02-08 14:14 ` Brijesh Singh
2022-01-28 17:18 ` [PATCH v9 43/43] virt: sevguest: Add support to get extended report Brijesh Singh
2022-02-01 20:43 ` Peter Gonda
2022-02-07 9:16 ` Borislav Petkov
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