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crypto: ccp - do not request interrupt on cmd completion when irqs disabled

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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: 8ef979584e ("crypto: ccp: Add panic notifier for SEV/SNP firmware shutdown on kdump")

Based-on-patch-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Amit Shah <amit.shah@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Amit Shah 2024-08-29 12:20:07 +02:00 committed by Herbert Xu
parent c299d7af9d
commit 3401f63e72
1 changed files with 12 additions and 1 deletions
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13
drivers/crypto/ccp/sev-dev.c
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@ -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 */