summaryrefslogtreecommitdiffstats
path: root/arch/x86/kvm/kvm_onhyperv.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kvm/kvm_onhyperv.c')
-rw-r--r--arch/x86/kvm/kvm_onhyperv.c108
1 files changed, 108 insertions, 0 deletions
diff --git a/arch/x86/kvm/kvm_onhyperv.c b/arch/x86/kvm/kvm_onhyperv.c
new file mode 100644
index 000000000..ee4f696a0
--- /dev/null
+++ b/arch/x86/kvm/kvm_onhyperv.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KVM L1 hypervisor optimizations on Hyper-V.
+ */
+
+#include <linux/kvm_host.h>
+#include <asm/mshyperv.h>
+
+#include "hyperv.h"
+#include "kvm_onhyperv.h"
+
+static int kvm_fill_hv_flush_list_func(struct hv_guest_mapping_flush_list *flush,
+ void *data)
+{
+ struct kvm_tlb_range *range = data;
+
+ return hyperv_fill_flush_guest_mapping_list(flush, range->start_gfn,
+ range->pages);
+}
+
+static inline int hv_remote_flush_root_tdp(hpa_t root_tdp,
+ struct kvm_tlb_range *range)
+{
+ if (range)
+ return hyperv_flush_guest_mapping_range(root_tdp,
+ kvm_fill_hv_flush_list_func, (void *)range);
+ else
+ return hyperv_flush_guest_mapping(root_tdp);
+}
+
+int hv_remote_flush_tlb_with_range(struct kvm *kvm,
+ struct kvm_tlb_range *range)
+{
+ struct kvm_arch *kvm_arch = &kvm->arch;
+ struct kvm_vcpu *vcpu;
+ int ret = 0, nr_unique_valid_roots;
+ unsigned long i;
+ hpa_t root;
+
+ spin_lock(&kvm_arch->hv_root_tdp_lock);
+
+ if (!VALID_PAGE(kvm_arch->hv_root_tdp)) {
+ nr_unique_valid_roots = 0;
+
+ /*
+ * Flush all valid roots, and see if all vCPUs have converged
+ * on a common root, in which case future flushes can skip the
+ * loop and flush the common root.
+ */
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ root = vcpu->arch.hv_root_tdp;
+ if (!VALID_PAGE(root) || root == kvm_arch->hv_root_tdp)
+ continue;
+
+ /*
+ * Set the tracked root to the first valid root. Keep
+ * this root for the entirety of the loop even if more
+ * roots are encountered as a low effort optimization
+ * to avoid flushing the same (first) root again.
+ */
+ if (++nr_unique_valid_roots == 1)
+ kvm_arch->hv_root_tdp = root;
+
+ if (!ret)
+ ret = hv_remote_flush_root_tdp(root, range);
+
+ /*
+ * Stop processing roots if a failure occurred and
+ * multiple valid roots have already been detected.
+ */
+ if (ret && nr_unique_valid_roots > 1)
+ break;
+ }
+
+ /*
+ * The optimized flush of a single root can't be used if there
+ * are multiple valid roots (obviously).
+ */
+ if (nr_unique_valid_roots > 1)
+ kvm_arch->hv_root_tdp = INVALID_PAGE;
+ } else {
+ ret = hv_remote_flush_root_tdp(kvm_arch->hv_root_tdp, range);
+ }
+
+ spin_unlock(&kvm_arch->hv_root_tdp_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(hv_remote_flush_tlb_with_range);
+
+int hv_remote_flush_tlb(struct kvm *kvm)
+{
+ return hv_remote_flush_tlb_with_range(kvm, NULL);
+}
+EXPORT_SYMBOL_GPL(hv_remote_flush_tlb);
+
+void hv_track_root_tdp(struct kvm_vcpu *vcpu, hpa_t root_tdp)
+{
+ struct kvm_arch *kvm_arch = &vcpu->kvm->arch;
+
+ if (kvm_x86_ops.tlb_remote_flush == hv_remote_flush_tlb) {
+ spin_lock(&kvm_arch->hv_root_tdp_lock);
+ vcpu->arch.hv_root_tdp = root_tdp;
+ if (root_tdp != kvm_arch->hv_root_tdp)
+ kvm_arch->hv_root_tdp = INVALID_PAGE;
+ spin_unlock(&kvm_arch->hv_root_tdp_lock);
+ }
+}
+EXPORT_SYMBOL_GPL(hv_track_root_tdp);