Subject: [PATCH 01/17] KVM: PPC: Book3E: Fix CONFIG_TRACE_IRQFLAGS support

From: Nicholas Piggin <[email-masked]>
Date: Sun, 27 Nov 2022 22:49:26 +1000

32-bit does not trace_irqs_off() to match the trace_irqs_on() call in
kvmppc_fix_ee_before_entry(). This can lead to irqs being enabled twice
in the trace, and the irqs-off region between guest exit and the host
enabling local irqs again is not properly traced.

64-bit code does call this, but from asm code where volatiles are live
and so incorrectly get clobbered.

Move the irq reconcile into C to fix both problems.

Signed-off-by: Nicholas Piggin <[email-masked]>
---
 arch/powerpc/include/asm/kvm_ppc.h    | 12 ++++++++++++
 arch/powerpc/kvm/booke.c              |  3 +++
 arch/powerpc/kvm/bookehv_interrupts.S |  9 ---------
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index bfacf12784dd..eae9619b6190 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -1014,6 +1014,18 @@ static inline void kvmppc_fix_ee_before_entry(void)
 #endif
 }
 
+static inline void kvmppc_fix_ee_after_exit(void)
+{
+#ifdef CONFIG_PPC64
+	/* Only need to enable IRQs by hard enabling them after this */
+	local_paca->irq_happened = PACA_IRQ_HARD_DIS;
+	irq_soft_mask_set(IRQS_ALL_DISABLED);
+#endif
+
+	trace_hardirqs_off();
+}
+
+
 static inline ulong kvmppc_get_ea_indexed(struct kvm_vcpu *vcpu, int ra, int rb)
 {
 	ulong ea;
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 7b4920e9fd26..0dce93ccaadf 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -1015,6 +1015,9 @@ int kvmppc_handle_exit(struct kvm_vcpu *vcpu, unsigned int exit_nr)
 	u32 last_inst = KVM_INST_FETCH_FAILED;
 	enum emulation_result emulated = EMULATE_DONE;
 
+	/* Fix irq state (pairs with kvmppc_fix_ee_before_entry()) */
+	kvmppc_fix_ee_after_exit();
+
 	/* update before a new last_exit_type is rewritten */
 	kvmppc_update_timing_stats(vcpu);
 
diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S
index 8262c14fc9e6..b5fe6fb53c66 100644
--- a/arch/powerpc/kvm/bookehv_interrupts.S
+++ b/arch/powerpc/kvm/bookehv_interrupts.S
@@ -424,15 +424,6 @@ _GLOBAL(kvmppc_resume_host)
 	mtspr	SPRN_EPCR, r3
 	isync
 
-#ifdef CONFIG_64BIT
-	/*
-	 * We enter with interrupts disabled in hardware, but
-	 * we need to call RECONCILE_IRQ_STATE to ensure
-	 * that the software state is kept in sync.
-	 */
-	RECONCILE_IRQ_STATE(r3,r5)
-#endif
-
 	/* Switch to kernel stack and jump to handler. */
 	mr	r3, r4
 	mr	r5, r14 /* intno */
-- 
2.37.2