From: Keqian Zhu <zhukeqian1@huawei.com>
To: <linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>, <kvm@vger.kernel.org>,
<kvmarm@lists.cs.columbia.edu>, Marc Zyngier <maz@kernel.org>
Cc: <wanghaibin.wang@huawei.com>
Subject: [PATCH v4 1/2] kvm/arm64: Remove the creation time's mapping of MMIO regions
Date: Thu, 15 Apr 2021 22:03:27 +0800 [thread overview]
Message-ID: <20210415140328.24200-2-zhukeqian1@huawei.com> (raw)
In-Reply-To: <20210415140328.24200-1-zhukeqian1@huawei.com>
The MMIO regions may be unmapped for many reasons and can be remapped
by stage2 fault path. Map MMIO regions at creation time becomes a
minor optimization and makes these two mapping path hard to sync.
Remove the mapping code while keep the useful sanity check.
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
---
arch/arm64/kvm/mmu.c | 38 +++-----------------------------------
1 file changed, 3 insertions(+), 35 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 8711894db8c2..c59af5ca01b0 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1301,7 +1301,6 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
{
hva_t hva = mem->userspace_addr;
hva_t reg_end = hva + mem->memory_size;
- bool writable = !(mem->flags & KVM_MEM_READONLY);
int ret = 0;
if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
@@ -1318,8 +1317,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
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.
+ * between them, so iterate over all of them.
*
* +--------------------------------------------+
* +---------------+----------------+ +----------------+
@@ -1330,50 +1328,20 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
*/
do {
struct vm_area_struct *vma = find_vma(current->mm, hva);
- hva_t vm_start, vm_end;
if (!vma || vma->vm_start >= reg_end)
break;
- /*
- * 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 = mem->guest_phys_addr +
- (vm_start - mem->userspace_addr);
- 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 (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) {
ret = -EINVAL;
- goto out;
- }
-
- ret = kvm_phys_addr_ioremap(kvm, gpa, pa,
- vm_end - vm_start,
- writable);
- if (ret)
break;
+ }
}
- hva = vm_end;
+ hva = min(reg_end, vma->vm_end);
} while (hva < reg_end);
- if (change == KVM_MR_FLAGS_ONLY)
- goto out;
-
- spin_lock(&kvm->mmu_lock);
- if (ret)
- unmap_stage2_range(&kvm->arch.mmu, mem->guest_phys_addr, mem->memory_size);
- else if (!cpus_have_final_cap(ARM64_HAS_STAGE2_FWB))
- stage2_flush_memslot(kvm, memslot);
- spin_unlock(&kvm->mmu_lock);
-out:
mmap_read_unlock(current->mm);
return ret;
}
--
2.19.1
next prev parent reply other threads:[~2021-04-15 14:03 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-15 14:03 [PATCH v4 0/2] kvm/arm64: Try stage2 block mapping for host device MMIO Keqian Zhu
2021-04-15 14:03 ` Keqian Zhu [this message]
2021-04-21 6:38 ` [PATCH v4 1/2] kvm/arm64: Remove the creation time's mapping of MMIO regions Gavin Shan
2021-04-21 6:28 ` Keqian Zhu
2021-04-22 2:12 ` Gavin Shan
2021-04-22 7:41 ` Keqian Zhu
2021-04-23 1:35 ` Gavin Shan
2021-04-23 1:36 ` Keqian Zhu
2021-04-23 0:36 ` Gavin Shan
2021-04-15 14:03 ` [PATCH v4 2/2] kvm/arm64: Try stage2 block mapping for host device MMIO Keqian Zhu
2021-04-15 14:08 ` Keqian Zhu
2021-04-16 14:44 ` Marc Zyngier
2021-04-17 1:05 ` Keqian Zhu
2021-04-21 7:52 ` Gavin Shan
2021-04-21 6:36 ` Keqian Zhu
2021-04-22 2:25 ` Gavin Shan
2021-04-22 6:51 ` Marc Zyngier
2021-04-23 0:42 ` Gavin Shan
2021-04-23 0:37 ` Gavin Shan
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