From ea138a607709bf72c162f62d2a670fe899d73daa Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Wed, 15 Oct 2025 17:17:09 -0700 Subject: [PATCH 1/3] RISC-V: KVM: Fix check for local interrupts on riscv32 To set all 64 bits in the mask on a 32-bit system, the constant must have type `unsigned long long`. Fixes: 6b1e8ba4bac4 ("RISC-V: KVM: Use bitmap for irqs_pending and irqs_pending_mask") Signed-off-by: Samuel Holland Reviewed-by: Andrew Jones Link: https://lore.kernel.org/r/20251016001714.3889380-1-samuel.holland@sifive.com Signed-off-by: Anup Patel --- arch/riscv/kvm/vcpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index bccb919ca615..5ce35aba6069 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -212,7 +212,7 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu) { - return (kvm_riscv_vcpu_has_interrupts(vcpu, -1UL) && + return (kvm_riscv_vcpu_has_interrupts(vcpu, -1ULL) && !kvm_riscv_vcpu_stopped(vcpu) && !vcpu->arch.pause); } From 873f10cf8e4d59605bc38fa1051dea8ee56fe3be Mon Sep 17 00:00:00 2001 From: Fangyu Yu Date: Thu, 16 Oct 2025 09:26:59 +0800 Subject: [PATCH 2/3] RISC-V: KVM: Read HGEIP CSR on the correct cpu When executing kvm_riscv_vcpu_aia_has_interrupts, the vCPU may have migrated and the IMSIC VS-file have not been updated yet, currently the HGEIP CSR should be read from the imsic->vsfile_cpu ( the pCPU before migration ) via on_each_cpu_mask, but this will trigger an IPI call and repeated IPI within a period of time is expensive in a many-core systems. Just let the vCPU execute and update the correct IMSIC VS-file via kvm_riscv_vcpu_aia_imsic_update may be a simple solution. Fixes: 4cec89db80ba ("RISC-V: KVM: Move HGEI[E|P] CSR access to IMSIC virtualization") Signed-off-by: Fangyu Yu Reviewed-by: Guo Ren Reviewed-by: Anup Patel Tested-by: Anup Patel Link: https://lore.kernel.org/r/20251016012659.82998-1-fangyu.yu@linux.alibaba.com Signed-off-by: Anup Patel --- arch/riscv/kvm/aia_imsic.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kvm/aia_imsic.c b/arch/riscv/kvm/aia_imsic.c index fda0346f0ea1..11422cb95a64 100644 --- a/arch/riscv/kvm/aia_imsic.c +++ b/arch/riscv/kvm/aia_imsic.c @@ -689,8 +689,20 @@ bool kvm_riscv_vcpu_aia_imsic_has_interrupt(struct kvm_vcpu *vcpu) */ read_lock_irqsave(&imsic->vsfile_lock, flags); - if (imsic->vsfile_cpu > -1) - ret = !!(csr_read(CSR_HGEIP) & BIT(imsic->vsfile_hgei)); + if (imsic->vsfile_cpu > -1) { + /* + * This function is typically called from kvm_vcpu_block() via + * kvm_arch_vcpu_runnable() upon WFI trap. The kvm_vcpu_block() + * can be preempted and the blocking VCPU might resume on a + * different CPU. This means it is possible that current CPU + * does not match the imsic->vsfile_cpu hence this function + * must check imsic->vsfile_cpu before accessing HGEIP CSR. + */ + if (imsic->vsfile_cpu != vcpu->cpu) + ret = true; + else + ret = !!(csr_read(CSR_HGEIP) & BIT(imsic->vsfile_hgei)); + } read_unlock_irqrestore(&imsic->vsfile_lock, flags); return ret; From 8c5fa3764facaad6d38336e90f406c2c11d69733 Mon Sep 17 00:00:00 2001 From: Fangyu Yu Date: Tue, 21 Oct 2025 22:21:31 +0800 Subject: [PATCH 3/3] RISC-V: KVM: Remove automatic I/O mapping for VM_PFNMAP As of commit aac6db75a9fc ("vfio/pci: Use unmap_mapping_range()"), vm_pgoff may no longer guaranteed to hold the PFN for VM_PFNMAP regions. Using vma->vm_pgoff to derive the HPA here may therefore produce incorrect mappings. Instead, I/O mappings for such regions can be established on-demand during g-stage page faults, making the upfront ioremap in this path is unnecessary. Fixes: aac6db75a9fc ("vfio/pci: Use unmap_mapping_range()") Signed-off-by: Fangyu Yu Tested-by: Daniel Henrique Barboza Reviewed-by: Guo Ren Reviewed-by: Anup Patel Link: https://lore.kernel.org/r/20251021142131.78796-1-fangyu.yu@linux.alibaba.com Signed-off-by: Anup Patel --- arch/riscv/kvm/mmu.c | 25 ++----------------------- 1 file changed, 2 insertions(+), 23 deletions(-) diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c index 525fb5a330c0..58f5f3536ffd 100644 --- a/arch/riscv/kvm/mmu.c +++ b/arch/riscv/kvm/mmu.c @@ -171,7 +171,6 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, enum kvm_mr_change change) { hva_t hva, reg_end, size; - gpa_t base_gpa; bool writable; int ret = 0; @@ -190,15 +189,13 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, hva = new->userspace_addr; size = new->npages << PAGE_SHIFT; reg_end = hva + size; - base_gpa = new->base_gfn << PAGE_SHIFT; writable = !(new->flags & KVM_MEM_READONLY); mmap_read_lock(current->mm); /* * A memory region could potentially cover multiple VMAs, and - * any holes between them, so iterate over all of them to find - * out if we can map any of them right now. + * any holes between them, so iterate over all of them. * * +--------------------------------------------+ * +---------------+----------------+ +----------------+ @@ -209,7 +206,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, */ do { struct vm_area_struct *vma; - hva_t vm_start, vm_end; + hva_t vm_end; vma = find_vma_intersection(current->mm, hva, reg_end); if (!vma) @@ -225,36 +222,18 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, } /* Take the intersection of this VMA with the memory region */ - vm_start = max(hva, vma->vm_start); vm_end = min(reg_end, vma->vm_end); if (vma->vm_flags & VM_PFNMAP) { - gpa_t gpa = base_gpa + (vm_start - hva); - phys_addr_t pa; - - pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT; - pa += vm_start - vma->vm_start; - /* IO region dirty page logging not allowed */ if (new->flags & KVM_MEM_LOG_DIRTY_PAGES) { ret = -EINVAL; goto out; } - - ret = kvm_riscv_mmu_ioremap(kvm, gpa, pa, vm_end - vm_start, - writable, false); - if (ret) - break; } hva = vm_end; } while (hva < reg_end); - if (change == KVM_MR_FLAGS_ONLY) - goto out; - - if (ret) - kvm_riscv_mmu_iounmap(kvm, base_gpa, size); - out: mmap_read_unlock(current->mm); return ret;