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>,
Wanpeng Li <wanpengli@tencent.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>,
tony.luck@intel.com, marcorr@google.com,
sathyanarayanan.kuppuswamy@linux.intel.com,
Brijesh Singh <brijesh.singh@amd.com>
Subject: [PATCH Part1 v5 08/38] x86/sev: Check SEV-SNP features support
Date: Fri, 20 Aug 2021 10:19:03 -0500 [thread overview]
Message-ID: <20210820151933.22401-9-brijesh.singh@amd.com> (raw)
In-Reply-To: <20210820151933.22401-1-brijesh.singh@amd.com>
Version 2 of the GHCB specification added the advertisement of features
that are supported by the hypervisor. If hypervisor supports the SEV-SNP
then it must set the SEV-SNP features bit to indicate that the base
SEV-SNP is supported.
Check the SEV-SNP feature while establishing the GHCB, if failed,
terminate the guest.
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
arch/x86/boot/compressed/sev.c | 26 ++++++++++++++++++++++++--
arch/x86/include/asm/sev-common.h | 3 +++
arch/x86/kernel/sev.c | 8 ++++++--
3 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 7760959fe96d..7be325d9b09f 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -25,6 +25,7 @@
struct ghcb boot_ghcb_page __aligned(PAGE_SIZE);
struct ghcb *boot_ghcb;
+static u64 msr_sev_status;
/*
* Copy a version of this function here - insn-eval.c can't be used in
@@ -119,11 +120,32 @@ static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
/* Include code for early handlers */
#include "../../kernel/sev-shared.c"
-static bool early_setup_sev_es(void)
+static inline bool sev_snp_enabled(void)
+{
+ unsigned long low, high;
+
+ if (!msr_sev_status) {
+ asm volatile("rdmsr\n"
+ : "=a" (low), "=d" (high)
+ : "c" (MSR_AMD64_SEV));
+ msr_sev_status = (high << 32) | low;
+ }
+
+ return msr_sev_status & MSR_AMD64_SEV_SNP_ENABLED;
+}
+
+static bool do_early_sev_setup(void)
{
if (!sev_es_negotiate_protocol())
sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_PROT_UNSUPPORTED);
+ /*
+ * If SEV-SNP is enabled, then check if the hypervisor supports the SEV-SNP
+ * features.
+ */
+ if (sev_snp_enabled() && !(sev_hv_features & GHCB_HV_FT_SNP))
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
if (set_page_decrypted((unsigned long)&boot_ghcb_page))
return false;
@@ -174,7 +196,7 @@ void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code)
struct es_em_ctxt ctxt;
enum es_result result;
- if (!boot_ghcb && !early_setup_sev_es())
+ if (!boot_ghcb && !do_early_sev_setup())
sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
vc_ghcb_invalidate(boot_ghcb);
diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
index 891569c07ed7..f80a3cde2086 100644
--- a/arch/x86/include/asm/sev-common.h
+++ b/arch/x86/include/asm/sev-common.h
@@ -64,6 +64,8 @@
/* GHCBData[63:12] */ \
(((u64)(v) & GENMASK_ULL(63, 12)) >> 12)
+#define GHCB_HV_FT_SNP BIT_ULL(0)
+
#define GHCB_MSR_TERM_REQ 0x100
#define GHCB_MSR_TERM_REASON_SET_POS 12
#define GHCB_MSR_TERM_REASON_SET_MASK 0xf
@@ -80,6 +82,7 @@
#define SEV_TERM_SET_GEN 0
#define GHCB_SEV_ES_GEN_REQ 0
#define GHCB_SEV_ES_PROT_UNSUPPORTED 1
+#define GHCB_SNP_UNSUPPORTED 2
/* Linux-specific reason codes (used with reason set 1) */
#define SEV_TERM_SET_LINUX 1
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 646912709334..06e6914cdc26 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -662,12 +662,16 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
* This function runs on the first #VC exception after the kernel
* switched to virtual addresses.
*/
-static bool __init sev_es_setup_ghcb(void)
+static bool __init setup_ghcb(void)
{
/* First make sure the hypervisor talks a supported protocol. */
if (!sev_es_negotiate_protocol())
return false;
+ /* If SNP is active, make sure that hypervisor supports the feature. */
+ if (sev_feature_enabled(SEV_SNP) && !(sev_hv_features & GHCB_HV_FT_SNP))
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
/*
* Clear the boot_ghcb. The first exception comes in before the bss
* section is cleared.
@@ -1476,7 +1480,7 @@ bool __init handle_vc_boot_ghcb(struct pt_regs *regs)
enum es_result result;
/* Do initial setup or terminate the guest */
- if (unlikely(boot_ghcb == NULL && !sev_es_setup_ghcb()))
+ if (unlikely(!boot_ghcb && !setup_ghcb()))
sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
vc_ghcb_invalidate(boot_ghcb);
--
2.17.1
next prev parent reply other threads:[~2021-08-20 15:21 UTC|newest]
Thread overview: 123+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 15:18 [PATCH Part1 v5 00/38] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Brijesh Singh
2021-08-20 15:18 ` [PATCH Part1 v5 01/38] x86/mm: Add sev_feature_enabled() helper Brijesh Singh
2021-08-20 15:18 ` [PATCH Part1 v5 02/38] x86/sev: Shorten GHCB terminate macro names Brijesh Singh
2021-08-20 15:18 ` [PATCH Part1 v5 03/38] x86/sev: Get rid of excessive use of defines Brijesh Singh
2021-08-20 15:18 ` [PATCH Part1 v5 04/38] x86/head64: Carve out the guest encryption postprocessing into a helper Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 05/38] x86/sev: Define the Linux specific guest termination reasons Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 06/38] x86/sev: Save the negotiated GHCB version Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 07/38] x86/sev: Add support for hypervisor feature VMGEXIT Brijesh Singh
2021-08-23 9:47 ` Borislav Petkov
2021-08-23 18:25 ` Brijesh Singh
2021-08-23 18:34 ` Brijesh Singh
2021-08-20 15:19 ` Brijesh Singh [this message]
2021-08-20 15:19 ` [PATCH Part1 v5 09/38] x86/sev: Add a helper for the PVALIDATE instruction Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 10/38] x86/sev: Check the vmpl level Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 11/38] x86/compressed: Add helper for validating pages in the decompression stage Brijesh Singh
2021-08-23 14:16 ` Borislav Petkov
2021-08-23 18:55 ` Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 12/38] x86/compressed: Register GHCB memory when SEV-SNP is active Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 13/38] x86/sev: " Brijesh Singh
2021-08-23 17:35 ` Borislav Petkov
2021-08-23 18:56 ` Brijesh Singh
2021-08-23 19:45 ` [PATCH] x86/sev: Remove do_early_exception() forward declarations Borislav Petkov
2021-08-23 20:06 ` Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 14/38] x86/sev: Add helper for validating pages in early enc attribute changes Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 15/38] x86/kernel: Make the bss.decrypted section shared in RMP table Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 16/38] x86/kernel: Validate rom memory before accessing when SEV-SNP is active Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 17/38] x86/mm: Add support to validate memory when changing C-bit Brijesh Singh
2021-08-25 11:06 ` Borislav Petkov
2021-08-25 13:54 ` Brijesh Singh
2021-08-25 14:00 ` Borislav Petkov
2021-08-27 17:09 ` Borislav Petkov
2021-08-20 15:19 ` [PATCH Part1 v5 18/38] KVM: SVM: Define sev_features and vmpl field in the VMSA Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 19/38] KVM: SVM: Create a separate mapping for the SEV-ES save area Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 20/38] KVM: SVM: Create a separate mapping for the GHCB " Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 21/38] KVM: SVM: Update the SEV-ES save area mapping Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 22/38] x86/sev: Use SEV-SNP AP creation to start secondary CPUs Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 23/38] x86/head/64: set up a startup %gs for stack protector Brijesh Singh
2021-08-25 14:29 ` Borislav Petkov
2021-08-25 15:18 ` Michael Roth
2021-08-25 16:29 ` Borislav Petkov
2021-08-27 13:38 ` Michael Roth
2021-08-31 8:03 ` Borislav Petkov
2021-08-31 23:30 ` Michael Roth
2021-08-25 15:07 ` Joerg Roedel
2021-08-25 17:07 ` Michael Roth
2021-08-20 15:19 ` [PATCH Part1 v5 24/38] x86/sev: move MSR-based VMGEXITs for CPUID to helper Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 25/38] KVM: x86: move lookup of indexed CPUID leafs " Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 26/38] x86/compressed/acpi: move EFI config table access to common code Brijesh Singh
2021-08-25 15:18 ` Borislav Petkov
2021-08-25 17:14 ` Michael Roth
2021-08-20 15:19 ` [PATCH Part1 v5 27/38] x86/boot: Add Confidential Computing type to setup_data Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 28/38] x86/compressed/64: enable SEV-SNP-validated CPUID in #VC handler Brijesh Singh
2021-08-25 19:19 ` Borislav Petkov
2021-08-27 16:46 ` Michael Roth
2021-08-31 10:04 ` Borislav Petkov
2021-09-01 1:03 ` Michael Roth
2021-09-02 10:53 ` Borislav Petkov
2021-08-20 15:19 ` [PATCH Part1 v5 29/38] x86/boot: add a pointer to Confidential Computing blob in bootparams Brijesh Singh
2021-08-27 13:51 ` Borislav Petkov
2021-08-27 18:48 ` Michael Roth
2021-08-20 15:19 ` [PATCH Part1 v5 30/38] x86/compressed/64: store Confidential Computing blob address " Brijesh Singh
2021-08-27 14:15 ` Borislav Petkov
2021-08-27 19:09 ` Michael Roth
2021-08-31 10:26 ` Borislav Petkov
2021-08-20 15:19 ` [PATCH Part1 v5 31/38] x86/compressed/64: add identity mapping for Confidential Computing blob Brijesh Singh
2021-08-27 14:43 ` Borislav Petkov
2021-08-20 15:19 ` [PATCH Part1 v5 32/38] x86/sev: enable SEV-SNP-validated CPUID in #VC handlers Brijesh Singh
2021-08-27 15:18 ` Borislav Petkov
2021-08-27 15:47 ` Brijesh Singh
2021-08-27 16:56 ` Borislav Petkov
2021-08-27 18:39 ` Michael Roth
2021-08-27 18:32 ` Michael Roth
2021-08-30 16:03 ` Michael Roth
2021-08-31 16:22 ` Borislav Petkov
2021-09-01 1:16 ` Michael Roth
2021-09-02 11:05 ` Borislav Petkov
2021-08-20 15:19 ` [PATCH Part1 v5 33/38] x86/sev: Provide support for SNP guest request NAEs Brijesh Singh
2021-08-27 17:44 ` Borislav Petkov
2021-08-27 18:07 ` Brijesh Singh
2021-08-27 18:13 ` Borislav Petkov
2021-08-27 18:27 ` Brijesh Singh
2021-08-27 18:38 ` Borislav Petkov
2021-08-27 19:57 ` Tom Lendacky
2021-08-27 20:17 ` Borislav Petkov
2021-08-27 20:31 ` Tom Lendacky
2021-08-20 15:19 ` [PATCH Part1 v5 34/38] x86/sev: Add snp_msg_seqno() helper Brijesh Singh
2021-08-27 18:41 ` Borislav Petkov
2021-08-30 15:07 ` Brijesh Singh
2021-09-02 11:26 ` Borislav Petkov
2021-09-02 15:27 ` Brijesh Singh
2021-08-31 20:46 ` Dov Murik
2021-08-31 21:13 ` Brijesh Singh
2021-09-09 14:54 ` Peter Gonda
2021-09-09 15:26 ` Brijesh Singh
2021-09-09 15:43 ` Peter Gonda
2021-09-09 16:17 ` Brijesh Singh
2021-09-09 16:21 ` Peter Gonda
2021-09-09 19:26 ` Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 35/38] x86/sev: Register SNP guest request platform device Brijesh Singh
2021-08-31 11:37 ` Dov Murik
2021-08-31 16:03 ` Brijesh Singh
2021-09-02 16:40 ` Borislav Petkov
2021-09-02 19:58 ` Brijesh Singh
2021-09-03 8:15 ` Dov Murik
2021-09-03 12:08 ` Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 36/38] virt: Add SEV-SNP guest driver Brijesh Singh
2021-09-06 17:38 ` Borislav Petkov
2021-09-07 13:35 ` Brijesh Singh
2021-09-08 13:44 ` Borislav Petkov
2021-08-20 15:19 ` [PATCH Part1 v5 37/38] virt: sevguest: Add support to derive key Brijesh Singh
2021-08-31 18:59 ` Dov Murik
2021-08-31 21:04 ` Brijesh Singh
2021-09-01 5:33 ` Dov Murik
2021-09-08 14:00 ` Borislav Petkov
2021-09-08 21:44 ` Brijesh Singh
2021-08-20 15:19 ` [PATCH Part1 v5 38/38] virt: sevguest: Add support to get extended report Brijesh Singh
2021-08-31 20:22 ` Dov Murik
2021-08-31 21:11 ` Brijesh Singh
2021-09-01 8:32 ` Dov Murik
2021-09-08 17:53 ` Borislav Petkov
2021-09-15 11:46 ` Brijesh Singh
2021-09-15 10:02 ` Dr. David Alan Gilbert
2021-09-15 11:53 ` Brijesh Singh
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