6.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Amit Shah <amit.shah@xxxxxxx>
[ Upstream commit 3401f63e72596dcb7d912a5b67b4291643cc1034 ]
While sending a command to the PSP, we always requested an interrupt
from the PSP after command completion. This worked for most cases. For
the special case of irqs being disabled -- e.g. when running within
crashdump or kexec contexts, we should not set the SEV_CMDRESP_IOC flag,
so the PSP knows to not attempt interrupt delivery.
Fixes: 8ef979584ea8 ("crypto: ccp: Add panic notifier for SEV/SNP firmware shutdown on kdump")
Based-on-patch-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Amit Shah <amit.shah@xxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/crypto/ccp/sev-dev.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 1912bee22dd4a..f2ad4653a58cb 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -910,7 +910,18 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret)
sev->int_rcvd = 0;
- reg = FIELD_PREP(SEV_CMDRESP_CMD, cmd) | SEV_CMDRESP_IOC;
+ reg = FIELD_PREP(SEV_CMDRESP_CMD, cmd);
+
+ /*
+ * If invoked during panic handling, local interrupts are disabled so
+ * the PSP command completion interrupt can't be used.
+ * sev_wait_cmd_ioc() already checks for interrupts disabled and
+ * polls for PSP command completion. Ensure we do not request an
+ * interrupt from the PSP if irqs disabled.
+ */
+ if (!irqs_disabled())
+ reg |= SEV_CMDRESP_IOC;
+
iowrite32(reg, sev->io_regs + sev->vdata->cmdresp_reg);
/* wait for command completion */
--
2.43.0
