[PATCH AUTOSEL 6.11 19/32] RISCV: KVM: use raw_spinlock for critical section in imsic

From: Sasha Levin
Date: Mon Oct 28 2024 - 06:56:09 EST


From: Cyan Yang <cyan.yang@xxxxxxxxxx>

[ Upstream commit 3ec4350d4efb5ccb6bd0e11d9cf7f2be4f47297d ]

For the external interrupt updating procedure in imsic, there was a
spinlock to protect it already. But since it should not be preempted in
any cases, we should turn to use raw_spinlock to prevent any preemption
in case PREEMPT_RT was enabled.

Signed-off-by: Cyan Yang <cyan.yang@xxxxxxxxxx>
Reviewed-by: Yong-Xuan Wang <yongxuan.wang@xxxxxxxxxx>
Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
Message-ID: <20240919160126.44487-1-cyan.yang@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/riscv/kvm/aia_imsic.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/kvm/aia_imsic.c b/arch/riscv/kvm/aia_imsic.c
index 0a1e859323b45..a8085cd8215e3 100644
--- a/arch/riscv/kvm/aia_imsic.c
+++ b/arch/riscv/kvm/aia_imsic.c
@@ -55,7 +55,7 @@ struct imsic {
/* IMSIC SW-file */
struct imsic_mrif *swfile;
phys_addr_t swfile_pa;
- spinlock_t swfile_extirq_lock;
+ raw_spinlock_t swfile_extirq_lock;
};

#define imsic_vs_csr_read(__c) \
@@ -622,7 +622,7 @@ static void imsic_swfile_extirq_update(struct kvm_vcpu *vcpu)
* interruptions between reading topei and updating pending status.
*/

- spin_lock_irqsave(&imsic->swfile_extirq_lock, flags);
+ raw_spin_lock_irqsave(&imsic->swfile_extirq_lock, flags);

if (imsic_mrif_atomic_read(mrif, &mrif->eidelivery) &&
imsic_mrif_topei(mrif, imsic->nr_eix, imsic->nr_msis))
@@ -630,7 +630,7 @@ static void imsic_swfile_extirq_update(struct kvm_vcpu *vcpu)
else
kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_EXT);

- spin_unlock_irqrestore(&imsic->swfile_extirq_lock, flags);
+ raw_spin_unlock_irqrestore(&imsic->swfile_extirq_lock, flags);
}

static void imsic_swfile_read(struct kvm_vcpu *vcpu, bool clear,
@@ -1051,7 +1051,7 @@ int kvm_riscv_vcpu_aia_imsic_init(struct kvm_vcpu *vcpu)
}
imsic->swfile = page_to_virt(swfile_page);
imsic->swfile_pa = page_to_phys(swfile_page);
- spin_lock_init(&imsic->swfile_extirq_lock);
+ raw_spin_lock_init(&imsic->swfile_extirq_lock);

/* Setup IO device */
kvm_iodevice_init(&imsic->iodev, &imsic_iodoev_ops);
--
2.43.0