@@ -658,8 +658,12 @@ static int __snp_cmd_buf_copy(int cmd, void *cmd_buf, bool to_fw, int fw_err)
* no not need to reclaim the page.
*/
if (from_fw && sev_legacy_cmd_buf_writable(cmd)) {
- if (rmp_mark_pages_shared(__pa(cmd_buf), 1))
+ if (psp_master->vdata->quirks & PSP_QUIRK_ALWAYS_RECLAIM) {
+ if (snp_reclaim_pages(__pa(cmd_buf), 1, true))
+ return -EFAULT;
+ } else if (rmp_mark_pages_shared(__pa(cmd_buf), 1)) {
return -EFAULT;
+ }
/* No need to go further if firmware failed to execute command. */
if (fw_err)
@@ -28,6 +28,9 @@
#define CACHE_NONE 0x00
#define CACHE_WB_NO_ALLOC 0xb7
+/* PSP requires a reclaim after every firmware command */
+#define PSP_QUIRK_ALWAYS_RECLAIM BIT(0)
+
/* Structure to hold CCP device data */
struct ccp_device;
struct ccp_vdata {
@@ -59,6 +62,7 @@ struct psp_vdata {
const unsigned int feature_reg;
const unsigned int inten_reg;
const unsigned int intsts_reg;
+ const unsigned int quirks;
};
/* Structure to hold SP device data */
@@ -103,6 +103,7 @@ static void sp_platform_fill_vdata(struct sp_dev_vdata *vdata,
.feature_reg = pdata->feature_reg,
.inten_reg = pdata->irq_en_reg,
.intsts_reg = pdata->irq_st_reg,
+ .quirks = PSP_QUIRK_ALWAYS_RECLAIM,
};
memcpy(sev, &sevtmp, sizeof(*sev));
On Hyper-V, the rmp_mark_pages_shared() call after a SEV_PLATFORM_STATUS fails with return code 2 (FAIL_PERMISSION) due to the page having the immutable bit set in the RMP (SNP has been initialized). The comment above this spot mentions that firmware automatically clears the immutable bit, but I can't find any mention of this behavior in the SNP Firmware ABI Spec. Introduce a quirk to always attempt the page reclaim and set it for the platform PSP. It would be possible to make this behavior unconditional as the firmware spec defines that page reclaim results in success if the page does not have the immutable bit set. Signed-off-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com> --- drivers/crypto/ccp/sev-dev.c | 6 +++++- drivers/crypto/ccp/sp-dev.h | 4 ++++ drivers/crypto/ccp/sp-platform.c | 1 + 3 files changed, 10 insertions(+), 1 deletion(-)