[PATCH v2 04/12] x86/sev: Do not hardcode GHCB protocol version
From: Joerg Roedel <joro@8bytes.org>
Date: 2021-09-13 15:56:37
Also in:
linux-coco, lkml, virtualization
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Joerg Roedel <redacted> Introduce the sev_get_ghcb_proto_ver() which will return the negotiated GHCB protocol version and use it to set the version field in the GHCB. Signed-off-by: Joerg Roedel <redacted> --- arch/x86/boot/compressed/sev.c | 5 +++++ arch/x86/kernel/sev-shared.c | 5 ++++- arch/x86/kernel/sev.c | 5 +++++ 3 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 1a2e49730f8b..101e08c67296 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c@@ -119,6 +119,11 @@ static enum es_result vc_read_mem(struct es_em_ctxt *ctxt, /* Include code for early handlers */ #include "../../kernel/sev-shared.c" +static u64 sev_get_ghcb_proto_ver(void) +{ + return GHCB_PROTOCOL_MAX; +} + static bool early_setup_sev_es(void) { if (!sev_es_negotiate_protocol(NULL))
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index 73eeb5897d16..36eaac2773ed 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c@@ -28,6 +28,9 @@ struct sev_ghcb_protocol_info { unsigned int vm_proto; }; +/* Returns the negotiated GHCB Protocol version */ +static u64 sev_get_ghcb_proto_ver(void); + static bool __init sev_es_check_cpu_features(void) { if (!has_cpuflag(X86_FEATURE_RDRAND)) {
@@ -122,7 +125,7 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, enum es_result ret; /* Fill in protocol and format specifiers */ - ghcb->protocol_version = GHCB_PROTOCOL_MAX; + ghcb->protocol_version = sev_get_ghcb_proto_ver(); ghcb->ghcb_usage = GHCB_DEFAULT_USAGE; ghcb_set_sw_exit_code(ghcb, exit_code);
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 8084bfd7cce1..5d3422e8b25e 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c@@ -498,6 +498,11 @@ static enum es_result vc_slow_virt_to_phys(struct ghcb *ghcb, struct es_em_ctxt /* Negotiated GHCB protocol version */ static struct sev_ghcb_protocol_info ghcb_protocol_info __ro_after_init; +static u64 sev_get_ghcb_proto_ver(void) +{ + return ghcb_protocol_info.vm_proto; +} + static noinstr void __sev_put_ghcb(struct ghcb_state *state) { struct sev_es_runtime_data *data;
--
2.33.0