KVM/riscv fixes for 6.18, take #2

- Fix check for local interrupts on riscv32
 - Read HGEIP CSR on the correct cpu when checking for IMSIC interrupts
 - Remove automatic I/O mapping from kvm_arch_prepare_memory_region()
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Merge tag 'kvm-riscv-fixes-6.18-2' of https://github.com/kvm-riscv/linux into HEAD

KVM/riscv fixes for 6.18, take #2

- Fix check for local interrupts on riscv32
- Read HGEIP CSR on the correct cpu when checking for IMSIC interrupts
- Remove automatic I/O mapping from kvm_arch_prepare_memory_region()

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;

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;

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);
 }