Merge tag 'for-4.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

[mirror_ubuntu-bionic-kernel.git] / arch / x86 / hyperv / mmu.c

diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c
index 39e7f6e50919117087fe663e013cd77d12b16b7b..9cc9e1c1e2dbcf6047c9ebd37f280c66b9e7e29a 100644 (file)
--- a/arch/x86/hyperv/mmu.c
+++ b/arch/x86/hyperv/mmu.c
@@ -36,9 +36,9 @@ struct hv_flush_pcpu_ex {
 /* Each gva in gva_list encodes up to 4096 pages to flush */
 #define HV_TLB_FLUSH_UNIT (4096 * PAGE_SIZE)
 
-static struct hv_flush_pcpu __percpu *pcpu_flush;
+static struct hv_flush_pcpu __percpu **pcpu_flush;
 
-static struct hv_flush_pcpu_ex __percpu *pcpu_flush_ex;
+static struct hv_flush_pcpu_ex __percpu **pcpu_flush_ex;
 
 /*
  * Fills in gva_list starting from offset. Returns the number of items added.
@@ -76,6 +76,18 @@ static inline int cpumask_to_vp_set(struct hv_flush_pcpu_ex *flush,
 {
        int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
 
+       /* valid_bank_mask can represent up to 64 banks */
+       if (hv_max_vp_index / 64 >= 64)
+               return 0;
+
+       /*
+        * Clear all banks up to the maximum possible bank as hv_flush_pcpu_ex
+        * structs are not cleared between calls, we risk flushing unneeded
+        * vCPUs otherwise.
+        */
+       for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
+               flush->hv_vp_set.bank_contents[vcpu_bank] = 0;
+
        /*
         * Some banks may end up being empty but this is acceptable.
         */
@@ -83,11 +95,6 @@ static inline int cpumask_to_vp_set(struct hv_flush_pcpu_ex *flush,
                vcpu = hv_cpu_number_to_vp_number(cpu);
                vcpu_bank = vcpu / 64;
                vcpu_offset = vcpu % 64;
-
-               /* valid_bank_mask can represent up to 64 banks */
-               if (vcpu_bank >= 64)
-                       return 0;
-
                __set_bit(vcpu_offset, (unsigned long *)
                          &flush->hv_vp_set.bank_contents[vcpu_bank]);
                if (vcpu_bank >= nr_bank)
@@ -102,6 +109,7 @@ 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_flush_pcpu **flush_pcpu;
        struct hv_flush_pcpu *flush;
        u64 status = U64_MAX;
        unsigned long flags;
@@ -116,7 +124,17 @@ static void hyperv_flush_tlb_others(const struct cpumask *cpus,
 
        local_irq_save(flags);
 
-       flush = this_cpu_ptr(pcpu_flush);
+       flush_pcpu = this_cpu_ptr(pcpu_flush);
+
+       if (unlikely(!*flush_pcpu))
+               *flush_pcpu = page_address(alloc_page(GFP_ATOMIC));
+
+       flush = *flush_pcpu;
+
+       if (unlikely(!flush)) {
+               local_irq_restore(flags);
+               goto do_native;
+       }
 
        if (info->mm) {
                flush->address_space = virt_to_phys(info->mm->pgd);
@@ -173,6 +191,7 @@ static void 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_flush_pcpu_ex **flush_pcpu;
        struct hv_flush_pcpu_ex *flush;
        u64 status = U64_MAX;
        unsigned long flags;
@@ -187,7 +206,17 @@ static void hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
 
        local_irq_save(flags);
 
-       flush = this_cpu_ptr(pcpu_flush_ex);
+       flush_pcpu = this_cpu_ptr(pcpu_flush_ex);
+
+       if (unlikely(!*flush_pcpu))
+               *flush_pcpu = page_address(alloc_page(GFP_ATOMIC));
+
+       flush = *flush_pcpu;
+
+       if (unlikely(!flush)) {
+               local_irq_restore(flags);
+               goto do_native;
+       }
 
        if (info->mm) {
                flush->address_space = virt_to_phys(info->mm->pgd);
@@ -222,18 +251,18 @@ static void hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
                flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
                status = hv_do_rep_hypercall(
                        HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
-                       0, nr_bank + 2, flush, NULL);
+                       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 + 2, flush, NULL);
+                       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 + 2, flush, NULL);
+                       gva_n, nr_bank, flush, NULL);
        }
 
        local_irq_restore(flags);
@@ -266,7 +295,7 @@ void hyper_alloc_mmu(void)
                return;
 
        if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
-               pcpu_flush = __alloc_percpu(PAGE_SIZE, PAGE_SIZE);
+               pcpu_flush = alloc_percpu(struct hv_flush_pcpu *);
        else
-               pcpu_flush_ex = __alloc_percpu(PAGE_SIZE, PAGE_SIZE);
+               pcpu_flush_ex = alloc_percpu(struct hv_flush_pcpu_ex *);
 }