Patch "RISCV: KVM: use raw_spinlock for critical section in imsic" has been added to the 6.11-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    RISCV: KVM: use raw_spinlock for critical section in imsic

to the 6.11-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     riscv-kvm-use-raw_spinlock-for-critical-section-in-i.patch
and it can be found in the queue-6.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 6000a1a00d5fd05d935adf0019db91c4628caf65
Author: Cyan Yang <cyan.yang@xxxxxxxxxx>
Date:   Fri Sep 20 00:01:26 2024 +0800

    RISCV: KVM: use raw_spinlock for critical section in imsic
    
    [ 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>

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);