From: Joerg Roedel <joro@8bytes.org>
To: x86@kernel.org, Eric Biederman <ebiederm@xmission.com>
Cc: kexec@lists.infradead.org, Joerg Roedel <jroedel@suse.de>,
hpa@zytor.com, Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Jiri Slaby <jslaby@suse.cz>,
Dan Williams <dan.j.williams@intel.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
Juergen Gross <jgross@suse.com>,
Kees Cook <keescook@chromium.org>,
David Rientjes <rientjes@google.com>,
Cfir Cohen <cfir@google.com>, Erdem Aktas <erdemaktas@google.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mike Stunes <mstunes@vmware.com>,
Sean Christopherson <seanjc@google.com>,
Martin Radev <martin.b.radev@gmail.com>,
Arvind Sankar <nivedita@alum.mit.edu>,
Joerg Roedel <joro@8bytes.org>,
linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, virtualization@lists.linux-foundation.org
Subject: [PATCH 03/12] x86/sev: Save and print negotiated GHCB protocol version
Date: Wed, 21 Jul 2021 16:20:06 +0200 [thread overview]
Message-ID: <20210721142015.1401-4-joro@8bytes.org> (raw)
In-Reply-To: <20210721142015.1401-1-joro@8bytes.org>
From: Joerg Roedel <jroedel@suse.de>
Save the results of the GHCB protocol negotiation into a data structure
and print information about versions supported and used to the kernel
log.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
arch/x86/boot/compressed/sev.c | 2 +-
arch/x86/kernel/sev-shared.c | 22 +++++++++++++++++++++-
arch/x86/kernel/sev.c | 13 ++++++++++++-
3 files changed, 34 insertions(+), 3 deletions(-)
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 670e998fe930..1a2e49730f8b 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -121,7 +121,7 @@ static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
static bool early_setup_sev_es(void)
{
- if (!sev_es_negotiate_protocol())
+ if (!sev_es_negotiate_protocol(NULL))
sev_es_terminate(GHCB_SEV_ES_REASON_PROTOCOL_UNSUPPORTED);
if (set_page_decrypted((unsigned long)&boot_ghcb_page))
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index 9f90f460a28c..73eeb5897d16 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -14,6 +14,20 @@
#define has_cpuflag(f) boot_cpu_has(f)
#endif
+/*
+ * struct sev_ghcb_protocol_info - Used to return GHCB protocol
+ * negotiation details.
+ *
+ * @hv_proto_min: Minimum GHCB protocol version supported by Hypervisor
+ * @hv_proto_max: Maximum GHCB protocol version supported by Hypervisor
+ * @vm_proto: Protocol version the VM (this kernel) will use
+ */
+struct sev_ghcb_protocol_info {
+ unsigned int hv_proto_min;
+ unsigned int hv_proto_max;
+ unsigned int vm_proto;
+};
+
static bool __init sev_es_check_cpu_features(void)
{
if (!has_cpuflag(X86_FEATURE_RDRAND)) {
@@ -42,7 +56,7 @@ static void __noreturn sev_es_terminate(unsigned int reason)
asm volatile("hlt\n" : : : "memory");
}
-static bool sev_es_negotiate_protocol(void)
+static bool sev_es_negotiate_protocol(struct sev_ghcb_protocol_info *info)
{
u64 val;
@@ -58,6 +72,12 @@ static bool sev_es_negotiate_protocol(void)
GHCB_MSR_PROTO_MIN(val) > GHCB_PROTO_OUR)
return false;
+ if (info) {
+ info->hv_proto_min = GHCB_MSR_PROTO_MIN(val);
+ info->hv_proto_max = GHCB_MSR_PROTO_MAX(val);
+ info->vm_proto = GHCB_PROTO_OUR;
+ }
+
return true;
}
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index a6895e440bc3..8084bfd7cce1 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -495,6 +495,9 @@ static enum es_result vc_slow_virt_to_phys(struct ghcb *ghcb, struct es_em_ctxt
/* Include code shared with pre-decompression boot stage */
#include "sev-shared.c"
+/* Negotiated GHCB protocol version */
+static struct sev_ghcb_protocol_info ghcb_protocol_info __ro_after_init;
+
static noinstr void __sev_put_ghcb(struct ghcb_state *state)
{
struct sev_es_runtime_data *data;
@@ -665,7 +668,7 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
static bool __init sev_es_setup_ghcb(void)
{
/* First make sure the hypervisor talks a supported protocol. */
- if (!sev_es_negotiate_protocol())
+ if (!sev_es_negotiate_protocol(&ghcb_protocol_info))
return false;
/*
@@ -794,6 +797,14 @@ void __init sev_es_init_vc_handling(void)
/* Secondary CPUs use the runtime #VC handler */
initial_vc_handler = (unsigned long)kernel_exc_vmm_communication;
+
+ /*
+ * Print information about supported and negotiated GHCB protocol
+ * versions.
+ */
+ pr_info("Hypervisor GHCB protocol version support: min=%u max=%u\n",
+ ghcb_protocol_info.hv_proto_min, ghcb_protocol_info.hv_proto_max);
+ pr_info("Using GHCB protocol version %u\n", ghcb_protocol_info.vm_proto);
}
static void __init vc_early_forward_exception(struct es_em_ctxt *ctxt)
--
2.31.1
next prev parent reply other threads:[~2021-07-21 14:21 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-21 14:20 [PATCH 00/12] x86/sev: KEXEC/KDUMP support for SEV-ES guests Joerg Roedel
2021-07-21 14:20 ` [PATCH 01/12] kexec: Allow architecture code to opt-out at runtime Joerg Roedel
2022-04-21 13:20 ` Tao Liu
2021-07-21 14:20 ` [PATCH 02/12] x86/kexec/64: Forbid kexec when running as an SEV-ES guest Joerg Roedel
2021-07-21 14:20 ` Joerg Roedel [this message]
2021-07-21 14:20 ` [PATCH 04/12] x86/sev: Do not hardcode GHCB protocol version Joerg Roedel
2021-07-21 21:17 ` Tom Lendacky
2021-07-31 7:18 ` Joerg Roedel
2021-07-21 14:20 ` [PATCH 05/12] x86/sev: Use GHCB protocol version 2 if supported Joerg Roedel
2021-07-21 14:20 ` [PATCH 06/12] x86/sev: Cache AP Jump Table Address Joerg Roedel
2021-07-21 14:20 ` [PATCH 07/12] x86/sev: Setup code to park APs in the AP Jump Table Joerg Roedel
2021-07-21 14:20 ` [PATCH 08/12] x86/sev: Park APs on AP Jump Table with GHCB protocol version 2 Joerg Roedel
2021-07-21 14:20 ` [PATCH 09/12] x86/sev: Use AP Jump Table blob to stop CPU Joerg Roedel
2021-07-21 14:20 ` [PATCH 10/12] x86/sev: Add MMIO handling support to boot/compressed/ code Joerg Roedel
2021-07-21 14:20 ` [PATCH 11/12] x86/sev: Handle CLFLUSH MMIO events Joerg Roedel
2021-07-30 22:42 ` Sean Christopherson
2021-07-31 7:17 ` Joerg Roedel
2021-07-21 14:20 ` [PATCH 12/12] x86/sev: Support kexec under SEV-ES with AP Jump Table blob Joerg Roedel
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