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#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;
cur += HV_TLB_FLUSH_UNIT;
} else if (diff) {
gva_list[gva_n] |= (diff - 1) >> PAGE_SHIFT;
cur = end;
}
gva_n++;
} while (cur < end);
return gva_n - offset;
}
static bool cpu_is_lazy(int cpu)
{
return per_cpu(cpu_tlbstate_shared.is_lazy, cpu);
}
static void hyperv_flush_tlb_multi(const struct cpumask *cpus,
const struct flush_tlb_info *info)
{
int cpu, vcpu, gva_n, max_gvas;
struct hv_tlb_flush *flush;
u64 status;
unsigned long flags;
bool do_lazy = !info->freed_tables;
trace_hyperv_mmu_flush_tlb_multi(cpus, info);
if (!hv_hypercall_pg)
goto do_native;
local_irq_save(flags);
flush = *this_cpu_ptr(hyperv_pcpu_input_arg);
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.
*/
cpu = cpumask_last(cpus);
if (cpu < nr_cpumask_bits && hv_cpu_number_to_vp_number(cpu) >= 64)
goto do_ex_hypercall;
for_each_cpu(cpu, cpus) {
if (do_lazy && cpu_is_lazy(cpu))
continue;
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);
}
/* nothing to flush if 'processor_mask' ends up being empty */
if (!flush->processor_mask) {
local_irq_restore(flags);
return;
}
}
/*
* 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 (hv_result_success(status))
return;
do_native:
native_flush_tlb_multi(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;
u64 status;
if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
return HV_STATUS_INVALID_PARAMETER;
flush = *this_cpu_ptr(hyperv_pcpu_input_arg);
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_skip(&flush->hv_vp_set, cpus,
info->freed_tables ? NULL : cpu_is_lazy);
if (nr_bank < 0)
return HV_STATUS_INVALID_PARAMETER;
/*
* 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_ops.mmu.flush_tlb_multi = hyperv_flush_tlb_multi;
pv_ops.mmu.tlb_remove_table = tlb_remove_table;
}
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