v4.19.13 snapshot.
diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c
new file mode 100644
index 0000000..ef5f29f
--- /dev/null
+++ b/arch/x86/hyperv/mmu.c
@@ -0,0 +1,236 @@
+#define pr_fmt(fmt) "Hyper-V: " fmt
+
+#include <linux/hyperv.h>
+#include <linux/log2.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <asm/fpu/api.h>
+#include <asm/mshyperv.h>
+#include <asm/msr.h>
+#include <asm/tlbflush.h>
+#include <asm/tlb.h>
+
+#define CREATE_TRACE_POINTS
+#include <asm/trace/hyperv.h>
+
+/* Each gva in gva_list encodes up to 4096 pages to flush */
+#define HV_TLB_FLUSH_UNIT (4096 * PAGE_SIZE)
+
+static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
+ const struct flush_tlb_info *info);
+
+/*
+ * Fills in gva_list starting from offset. Returns the number of items added.
+ */
+static inline int fill_gva_list(u64 gva_list[], int offset,
+ unsigned long start, unsigned long end)
+{
+ int gva_n = offset;
+ unsigned long cur = start, diff;
+
+ do {
+ diff = end > cur ? end - cur : 0;
+
+ gva_list[gva_n] = cur & PAGE_MASK;
+ /*
+ * Lower 12 bits encode the number of additional
+ * pages to flush (in addition to the 'cur' page).
+ */
+ if (diff >= HV_TLB_FLUSH_UNIT)
+ gva_list[gva_n] |= ~PAGE_MASK;
+ else if (diff)
+ gva_list[gva_n] |= (diff - 1) >> PAGE_SHIFT;
+
+ cur += HV_TLB_FLUSH_UNIT;
+ gva_n++;
+
+ } while (cur < end);
+
+ return gva_n - offset;
+}
+
+static void hyperv_flush_tlb_others(const struct cpumask *cpus,
+ const struct flush_tlb_info *info)
+{
+ int cpu, vcpu, gva_n, max_gvas;
+ struct hv_tlb_flush **flush_pcpu;
+ struct hv_tlb_flush *flush;
+ u64 status = U64_MAX;
+ unsigned long flags;
+
+ trace_hyperv_mmu_flush_tlb_others(cpus, info);
+
+ if (!hv_hypercall_pg)
+ goto do_native;
+
+ if (cpumask_empty(cpus))
+ return;
+
+ local_irq_save(flags);
+
+ flush_pcpu = (struct hv_tlb_flush **)
+ this_cpu_ptr(hyperv_pcpu_input_arg);
+
+ flush = *flush_pcpu;
+
+ if (unlikely(!flush)) {
+ local_irq_restore(flags);
+ goto do_native;
+ }
+
+ if (info->mm) {
+ /*
+ * AddressSpace argument must match the CR3 with PCID bits
+ * stripped out.
+ */
+ flush->address_space = virt_to_phys(info->mm->pgd);
+ flush->address_space &= CR3_ADDR_MASK;
+ flush->flags = 0;
+ } else {
+ flush->address_space = 0;
+ flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
+ }
+
+ flush->processor_mask = 0;
+ if (cpumask_equal(cpus, cpu_present_mask)) {
+ flush->flags |= HV_FLUSH_ALL_PROCESSORS;
+ } else {
+ /*
+ * From the supplied CPU set we need to figure out if we can get
+ * away with cheaper HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}
+ * hypercalls. This is possible when the highest VP number in
+ * the set is < 64. As VP numbers are usually in ascending order
+ * and match Linux CPU ids, here is an optimization: we check
+ * the VP number for the highest bit in the supplied set first
+ * so we can quickly find out if using *_EX hypercalls is a
+ * must. We will also check all VP numbers when walking the
+ * supplied CPU set to remain correct in all cases.
+ */
+ if (hv_cpu_number_to_vp_number(cpumask_last(cpus)) >= 64)
+ goto do_ex_hypercall;
+
+ for_each_cpu(cpu, cpus) {
+ vcpu = hv_cpu_number_to_vp_number(cpu);
+ if (vcpu == VP_INVAL) {
+ local_irq_restore(flags);
+ goto do_native;
+ }
+
+ if (vcpu >= 64)
+ goto do_ex_hypercall;
+
+ __set_bit(vcpu, (unsigned long *)
+ &flush->processor_mask);
+ }
+ }
+
+ /*
+ * We can flush not more than max_gvas with one hypercall. Flush the
+ * whole address space if we were asked to do more.
+ */
+ max_gvas = (PAGE_SIZE - sizeof(*flush)) / sizeof(flush->gva_list[0]);
+
+ if (info->end == TLB_FLUSH_ALL) {
+ flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
+ status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
+ flush, NULL);
+ } else if (info->end &&
+ ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
+ status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
+ flush, NULL);
+ } else {
+ gva_n = fill_gva_list(flush->gva_list, 0,
+ info->start, info->end);
+ status = hv_do_rep_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST,
+ gva_n, 0, flush, NULL);
+ }
+ goto check_status;
+
+do_ex_hypercall:
+ status = hyperv_flush_tlb_others_ex(cpus, info);
+
+check_status:
+ local_irq_restore(flags);
+
+ if (!(status & HV_HYPERCALL_RESULT_MASK))
+ return;
+do_native:
+ native_flush_tlb_others(cpus, info);
+}
+
+static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
+ const struct flush_tlb_info *info)
+{
+ int nr_bank = 0, max_gvas, gva_n;
+ struct hv_tlb_flush_ex **flush_pcpu;
+ struct hv_tlb_flush_ex *flush;
+ u64 status;
+
+ if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
+ return U64_MAX;
+
+ flush_pcpu = (struct hv_tlb_flush_ex **)
+ this_cpu_ptr(hyperv_pcpu_input_arg);
+
+ flush = *flush_pcpu;
+
+ if (info->mm) {
+ /*
+ * AddressSpace argument must match the CR3 with PCID bits
+ * stripped out.
+ */
+ flush->address_space = virt_to_phys(info->mm->pgd);
+ flush->address_space &= CR3_ADDR_MASK;
+ flush->flags = 0;
+ } else {
+ flush->address_space = 0;
+ flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
+ }
+
+ flush->hv_vp_set.valid_bank_mask = 0;
+
+ flush->hv_vp_set.format = HV_GENERIC_SET_SPARSE_4K;
+ nr_bank = cpumask_to_vpset(&(flush->hv_vp_set), cpus);
+ if (nr_bank < 0)
+ return U64_MAX;
+
+ /*
+ * We can flush not more than max_gvas with one hypercall. Flush the
+ * whole address space if we were asked to do more.
+ */
+ max_gvas =
+ (PAGE_SIZE - sizeof(*flush) - nr_bank *
+ sizeof(flush->hv_vp_set.bank_contents[0])) /
+ sizeof(flush->gva_list[0]);
+
+ if (info->end == TLB_FLUSH_ALL) {
+ flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
+ status = hv_do_rep_hypercall(
+ HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
+ 0, nr_bank, flush, NULL);
+ } else if (info->end &&
+ ((info->end - info->start)/HV_TLB_FLUSH_UNIT) > max_gvas) {
+ status = hv_do_rep_hypercall(
+ HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
+ 0, nr_bank, flush, NULL);
+ } else {
+ gva_n = fill_gva_list(flush->gva_list, nr_bank,
+ info->start, info->end);
+ status = hv_do_rep_hypercall(
+ HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX,
+ gva_n, nr_bank, flush, NULL);
+ }
+
+ return status;
+}
+
+void hyperv_setup_mmu_ops(void)
+{
+ if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED))
+ return;
+
+ pr_info("Using hypercall for remote TLB flush\n");
+ pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others;
+ pv_mmu_ops.tlb_remove_table = tlb_remove_table;
+}