From: Brijesh Singh <brijesh.singh@amd.com>
To: x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: tglx@linutronix.de, bp@alien8.de, jroedel@suse.de,
thomas.lendacky@amd.com, pbonzini@redhat.com, mingo@redhat.com,
dave.hansen@intel.com, rientjes@google.com, seanjc@google.com,
peterz@infradead.org, hpa@zytor.com, tony.luck@intel.com,
Brijesh Singh <brijesh.singh@amd.com>
Subject: [PATCH Part1 RFC v2 12/20] x86/compressed: Register GHCB memory when SEV-SNP is active
Date: Fri, 30 Apr 2021 07:16:08 -0500 [thread overview]
Message-ID: <20210430121616.2295-13-brijesh.singh@amd.com> (raw)
In-Reply-To: <20210430121616.2295-1-brijesh.singh@amd.com>
The SEV-SNP guest is required to perform GHCB GPA registration. This is
because the hypervisor may prefer that a guest use a consistent and/or
specific GPA for the GHCB associated with a vCPU. For more information,
see the GHCB specification.
If hypervisor can not work with the guest provided GPA then terminate the
guest boot.
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
arch/x86/boot/compressed/sev.c | 4 ++++
arch/x86/include/asm/sev-common.h | 12 ++++++++++++
arch/x86/kernel/sev-shared.c | 16 ++++++++++++++++
3 files changed, 32 insertions(+)
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 4f215d0c9f76..07b9529d7d95 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -206,6 +206,10 @@ static bool early_setup_sev_es(void)
/* Initialize lookup tables for the instruction decoder */
inat_init_tables();
+ /* SEV-SNP guest requires the GHCB GPA must be registered */
+ if (sev_snp_enabled())
+ snp_register_ghcb(__pa(&boot_ghcb_page));
+
return true;
}
diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
index 733fca403ae5..7487d4768ef0 100644
--- a/arch/x86/include/asm/sev-common.h
+++ b/arch/x86/include/asm/sev-common.h
@@ -88,6 +88,18 @@
#define GHCB_MSR_PSC_RSVD_MASK 0xfffffULL
#define GHCB_MSR_PSC_RESP_VAL(val) ((val) >> GHCB_MSR_PSC_ERROR_POS)
+/* GHCB GPA Register */
+#define GHCB_MSR_GPA_REG_REQ 0x012
+#define GHCB_MSR_GPA_REG_VALUE_POS 12
+#define GHCB_MSR_GPA_REG_VALUE_MASK 0xfffffffffffffULL
+#define GHCB_MSR_GPA_REQ_VAL(v) \
+ (((v) << GHCB_MSR_GPA_REG_VALUE_POS) | GHCB_MSR_GPA_REG_REQ)
+
+#define GHCB_MSR_GPA_REG_RESP 0x013
+#define GHCB_MSR_GPA_REG_RESP_VAL(v) ((v) >> GHCB_MSR_GPA_REG_VALUE_POS)
+#define GHCB_MSR_GPA_REG_ERROR 0xfffffffffffffULL
+#define GHCB_MSR_GPA_INVALID ~0ULL
+
/* SNP Page State Change NAE event */
#define VMGEXIT_PSC_MAX_ENTRY 253
#define VMGEXIT_PSC_INVALID_HEADER 0x100000001
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index 085d3d724bc8..140c5bc07fc2 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -81,6 +81,22 @@ static bool ghcb_get_hv_features(void)
return true;
}
+static void snp_register_ghcb(unsigned long paddr)
+{
+ unsigned long pfn = paddr >> PAGE_SHIFT;
+ u64 val;
+
+ sev_es_wr_ghcb_msr(GHCB_MSR_GPA_REQ_VAL(pfn));
+ VMGEXIT();
+
+ val = sev_es_rd_ghcb_msr();
+
+ /* If the response GPA is not ours then abort the guest */
+ if ((GHCB_RESP_CODE(val) != GHCB_MSR_GPA_REG_RESP) ||
+ (GHCB_MSR_GPA_REG_RESP_VAL(val) != pfn))
+ sev_es_terminate(1, GHCB_TERM_REGISTER);
+}
+
static bool sev_es_negotiate_protocol(void)
{
u64 val;
--
2.17.1
next prev parent reply other threads:[~2021-04-30 12:17 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-30 12:15 [PATCH Part1 RFC v2 00/20] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Brijesh Singh
2021-04-30 12:15 ` [PATCH Part1 RFC v2 01/20] x86/sev: Define the GHCB MSR protocol for AP reset hold Brijesh Singh
2021-04-30 12:15 ` [PATCH Part1 RFC v2 02/20] x86/sev: Save the negotiated GHCB version Brijesh Singh
2021-05-11 9:23 ` Borislav Petkov
2021-05-11 18:29 ` Brijesh Singh
2021-05-11 18:41 ` Borislav Petkov
2021-05-12 14:03 ` Brijesh Singh
2021-05-12 14:31 ` Borislav Petkov
2021-05-12 15:03 ` Brijesh Singh
2021-04-30 12:15 ` [PATCH Part1 RFC v2 03/20] x86/sev: Add support for hypervisor feature VMGEXIT Brijesh Singh
2021-05-11 10:01 ` Borislav Petkov
2021-05-11 18:53 ` Brijesh Singh
2021-05-17 14:40 ` Borislav Petkov
2021-04-30 12:16 ` [PATCH Part1 RFC v2 04/20] x86/sev: Increase the GHCB protocol version Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 05/20] x86/sev: Define SNP Page State Change VMGEXIT structure Brijesh Singh
2021-05-18 10:41 ` Borislav Petkov
2021-05-18 15:06 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 06/20] x86/sev: Define SNP guest request NAE events Brijesh Singh
2021-05-18 10:45 ` Borislav Petkov
2021-05-18 13:42 ` Brijesh Singh
2021-05-18 13:54 ` Borislav Petkov
2021-05-18 14:13 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 07/20] x86/sev: Define error codes for reason set 1 Brijesh Singh
2021-05-18 11:05 ` Borislav Petkov
2021-04-30 12:16 ` [PATCH Part1 RFC v2 08/20] x86/mm: Add sev_snp_active() helper Brijesh Singh
2021-05-18 18:11 ` Borislav Petkov
2021-05-19 17:28 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 09/20] x86/sev: check SEV-SNP features support Brijesh Singh
2021-05-20 16:02 ` Borislav Petkov
2021-05-20 17:40 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 10/20] x86/sev: Add a helper for the PVALIDATE instruction Brijesh Singh
2021-04-30 13:05 ` Brijesh Singh
2021-05-20 17:32 ` Borislav Petkov
2021-05-20 17:44 ` Brijesh Singh
2021-05-20 17:51 ` Borislav Petkov
2021-05-20 17:57 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 11/20] x86/compressed: Add helper for validating pages in the decompression stage Brijesh Singh
2021-05-20 17:52 ` Borislav Petkov
2021-05-20 18:05 ` Brijesh Singh
2021-05-25 10:18 ` Borislav Petkov
2021-04-30 12:16 ` Brijesh Singh [this message]
2021-05-25 10:41 ` [PATCH Part1 RFC v2 12/20] x86/compressed: Register GHCB memory when SEV-SNP is active Borislav Petkov
2021-04-30 12:16 ` [PATCH Part1 RFC v2 13/20] x86/sev: " Brijesh Singh
2021-05-25 11:11 ` Borislav Petkov
2021-05-25 14:28 ` Brijesh Singh
2021-05-25 14:35 ` Borislav Petkov
2021-05-25 14:47 ` Brijesh Singh
2021-05-26 9:57 ` Borislav Petkov
2021-05-26 13:23 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 14/20] x86/sev: Add helper for validating pages in early enc attribute changes Brijesh Singh
2021-05-26 10:39 ` Borislav Petkov
2021-05-26 13:34 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 15/20] x86/kernel: Make the bss.decrypted section shared in RMP table Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 16/20] x86/kernel: Validate rom memory before accessing when SEV-SNP is active Brijesh Singh
2021-05-27 11:49 ` Borislav Petkov
2021-05-27 12:12 ` Brijesh Singh
2021-05-27 12:23 ` Borislav Petkov
2021-05-27 12:56 ` Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 17/20] x86/mm: Add support to validate memory when changing C-bit Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 18/20] x86/boot: Add Confidential Computing address to setup_header Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 19/20] x86/sev: Register SNP guest request platform device Brijesh Singh
2021-04-30 12:16 ` [PATCH Part1 RFC v2 20/20] virt: Add SEV-SNP guest driver Brijesh Singh
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