[PATCH v3 4/7] x86/sev-es: Run #VC handler in plain IRQ state

From: Joerg Roedel
Date: Tue Jun 08 2021 - 05:55:00 EST


From: Joerg Roedel <jroedel@xxxxxxx>

Use irqentry_enter() and irqentry_exit() to track the runtime state of
the #VC handler. The reason it ran in NMI mode was solely to make sure
nothing interrupts the handler while the GHCB is in use.

This is handled now in sev_es_get/put_ghcb() directly, so there is no
reason the #VC handler can not run in normal IRQ mode and enjoy the
benefits like being able to send signals.

Fixes: 62441a1fb532 ("x86/sev-es: Correctly track IRQ states in runtime #VC handler")
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
arch/x86/kernel/sev.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 2a922d1b03c8..b563fb747aed 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -1354,8 +1354,7 @@ DEFINE_IDTENTRY_VC_SAFE_STACK(exc_vmm_communication)
return;
}

- irq_state = irqentry_nmi_enter(regs);
- lockdep_assert_irqs_disabled();
+ irq_state = irqentry_enter(regs);
instrumentation_begin();

/*
@@ -1408,7 +1407,7 @@ DEFINE_IDTENTRY_VC_SAFE_STACK(exc_vmm_communication)

out:
instrumentation_end();
- irqentry_nmi_exit(regs, irq_state);
+ irqentry_exit(regs, irq_state);

return;

--
2.31.1