The PSP advertises the SEV-TIO support via the FEATURE_INFO command
advertised via SNP_PLATFORM_STATUS.
The BIOS advertises the SEV-TIO enablement via the IOMMU EFR2 register
(added in an earlier patch).
Enable SEV-TIO during the SNP_INIT_EX call if both the PSP and the BIOS
advertise support for it.
Signed-off-by: Alexey Kardashevskiy <aik@amd.com>
---
include/linux/psp-sev.h | 4 +++-
drivers/crypto/ccp/sev-dev.c | 10 +++++++++-
2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index e3db92e9c687..6162cf5dccde 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -750,7 +750,8 @@ struct sev_data_snp_init_ex {
u32 list_paddr_en:1;
u32 rapl_dis:1;
u32 ciphertext_hiding_en:1;
- u32 rsvd:28;
+ u32 tio_en:1;
+ u32 rsvd:27;
u32 rsvd1;
u64 list_paddr;
u16 max_snp_asid;
@@ -850,6 +851,7 @@ struct snp_feature_info {
} __packed;
#define SNP_CIPHER_TEXT_HIDING_SUPPORTED BIT(3)
+#define SNP_SEV_TIO_SUPPORTED BIT(1) /* EBX */
#ifdef CONFIG_CRYPTO_DEV_SP_PSP
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 9e0c16b36f9c..2f1c9614d359 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -1358,6 +1358,11 @@ static int snp_filter_reserved_mem_regions(struct resource *rs, void *arg)
return 0;
}
+static bool sev_tio_present(struct sev_device *sev)
+{
+ return (sev->snp_feat_info_0.ebx & SNP_SEV_TIO_SUPPORTED) != 0;
+}
+
static int __sev_snp_init_locked(int *error, unsigned int max_snp_asid)
{
struct psp_device *psp = psp_master;
@@ -1434,6 +1439,8 @@ static int __sev_snp_init_locked(int *error, unsigned int max_snp_asid)
data.init_rmp = 1;
data.list_paddr_en = 1;
data.list_paddr = __psp_pa(snp_range_list);
+ data.tio_en = sev_tio_present(sev) &&
+ amd_iommu_sev_tio_supported();
cmd = SEV_CMD_SNP_INIT_EX;
} else {
cmd = SEV_CMD_SNP_INIT;
@@ -1471,7 +1478,8 @@ static int __sev_snp_init_locked(int *error, unsigned int max_snp_asid)
snp_hv_fixed_pages_state_update(sev, HV_FIXED);
sev->snp_initialized = true;
- dev_dbg(sev->dev, "SEV-SNP firmware initialized\n");
+ dev_dbg(sev->dev, "SEV-SNP firmware initialized, SEV-TIO is %s\n",
+ data.tio_en ? "enabled" : "disabled");
dev_info(sev->dev, "SEV-SNP API:%d.%d build:%d\n", sev->api_major,
sev->api_minor, sev->build);
--
2.51.0