[V2,2/13] KVM/MMU: Add tlb flush with range helper function

Commit Message

Tianyu Lan Sept. 18, 2018, 3:18 a.m. UTC

This patch is to add wrapper functions for tlb_remote_flush_with_range
callback.

Signed-off-by: Lan Tianyu <[e-mail]>
---
 arch/x86/kvm/mmu.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

Comments

Michael Kelley (EOSG) Sept. 19, 2018, 4:07 p.m. UTC | #1

From: Tianyu Lan  Sent: Monday, September 17, 2018 8:18 PM
>
> +static void kvm_flush_remote_tlbs_with_range(struct kvm *kvm,
> +		struct kvm_tlb_range *range)
> +{
> +	int ret = -ENOTSUPP;
> +
> +	if (range && kvm_x86_ops->tlb_remote_flush_with_range) {
> +		/*
> +		 * Read tlbs_dirty before setting KVM_REQ_TLB_FLUSH in
> +		 * kvm_make_all_cpus_request.
> +		 */
> +		long dirty_count = smp_load_acquire(&kvm->tlbs_dirty);
> +
> +		ret = kvm_x86_ops->tlb_remote_flush_with_range(kvm, range);
> +		cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
> +	}

The comment and the code that manipulates kvm->tlbs_dirty appears
to have been copied from kvm_flush_remote_tlbs().  But the above
code doesn't call kvm_make_all_cpus_request().   I haven't traced
all the details, but it seems like the comment should be updated,
or the code isn't needed.

Michael

Patch

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index c67f09086378..ac3b748f58f8 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -253,6 +253,54 @@  static void mmu_spte_set(u64 *sptep, u64 spte);
 static union kvm_mmu_page_role
 kvm_mmu_calc_root_page_role(struct kvm_vcpu *vcpu);
 
+
+static inline bool kvm_available_flush_tlb_with_range(void)
+{
+	return kvm_x86_ops->tlb_remote_flush_with_range;
+}
+
+static void kvm_flush_remote_tlbs_with_range(struct kvm *kvm,
+		struct kvm_tlb_range *range)
+{
+	int ret = -ENOTSUPP;
+
+	if (range && kvm_x86_ops->tlb_remote_flush_with_range) {
+		/*
+		 * Read tlbs_dirty before setting KVM_REQ_TLB_FLUSH in
+		 * kvm_make_all_cpus_request.
+		 */
+		long dirty_count = smp_load_acquire(&kvm->tlbs_dirty);
+
+		ret = kvm_x86_ops->tlb_remote_flush_with_range(kvm, range);
+		cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
+	}
+
+	if (ret)
+		kvm_flush_remote_tlbs(kvm);
+}
+
+static void kvm_flush_remote_tlbs_with_list(struct kvm *kvm,
+		struct list_head *flush_list)
+{
+	struct kvm_tlb_range range;
+
+	range.flush_list = flush_list;
+
+	kvm_flush_remote_tlbs_with_range(kvm, &range);
+}
+
+static void kvm_flush_remote_tlbs_with_address(struct kvm *kvm,
+		u64 start_gfn, u64 pages)
+{
+	struct kvm_tlb_range range;
+
+	range.start_gfn = start_gfn;
+	range.pages = pages;
+	range.flush_list = NULL;
+
+	kvm_flush_remote_tlbs_with_range(kvm, &range);
+}
+
 void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask, u64 mmio_value)
 {
 	BUG_ON((mmio_mask & mmio_value) != mmio_value);