From: Michael Kelley <mhkli...@outlook.com>

Update hypercall call sites to use the new hv_hvcall_*() functions
to set up hypercall arguments. Since these functions zero the
fixed portion of input memory, remove now redundant calls to memset()
and explicit zero'ing of input fields.

For hv_mark_gpa_visibility(), use the computed batch_size instead
of HV_MAX_MODIFY_GPA_REP_COUNT. Also update the associated gpa_page_list[]
field to have zero size, which is more consistent with other array
arguments to hypercalls. Due to the interaction with the calling
hv_vtom_set_host_visibility(), HV_MAX_MODIFY_GPA_REP_COUNT cannot be
completely eliminated without some further restructuring, but that's
for another patch set.

Similarly, for the nested flush functions, update the gpa_list[] to
have zero size. Again, separate restructuring would be required to
completely eliminate the need for HV_MAX_FLUSH_REP_COUNT.

Finally, hyperv_flush_tlb_others_ex() requires special handling
because the input consists of two arrays -- one for the hv_vp_set and
another for the gva list. The batch_size computed by hv_hvcall_in_array()
is adjusted to account for the number of entries in the hv_vp_set.

Signed-off-by: Michael Kelley <mhkli...@outlook.com>
---

Notes:
    Changes in v2:
    * In hyperv_flush_tlb_others_ex(), added check of the adjusted
      max_gvas to make sure it doesn't go to zero or negative, which would
      happen if there is insufficient space to hold the hv_vpset and have
      at least one entry in the gva list. Since an hv_vpset currently
      represents a maximum of 4096 CPUs, the hv_vpset size does not exceed
      512 bytes and there should always be sufficent space. But do the
      check just in case something changes. [Nuno Das Neves]

 arch/x86/hyperv/ivm.c       | 18 +++++++++---------
 arch/x86/hyperv/mmu.c       | 19 +++++--------------
 arch/x86/hyperv/nested.c    | 14 +++++---------
 include/hyperv/hvgdk_mini.h |  4 ++--
 4 files changed, 21 insertions(+), 34 deletions(-)

diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index ec7880271cf9..de983aae0cbe 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -465,30 +465,30 @@ static int hv_mark_gpa_visibility(u16 count, const u64 
pfn[],
 {
        struct hv_gpa_range_for_visibility *input;
        u64 hv_status;
+       int batch_size;
        unsigned long flags;
 
        /* no-op if partition isolation is not enabled */
        if (!hv_is_isolation_supported())
                return 0;
 
-       if (count > HV_MAX_MODIFY_GPA_REP_COUNT) {
-               pr_err("Hyper-V: GPA count:%d exceeds supported:%lu\n", count,
-                       HV_MAX_MODIFY_GPA_REP_COUNT);
+       local_irq_save(flags);
+       batch_size = hv_hvcall_in_array(&input, sizeof(*input),
+                                       sizeof(input->gpa_page_list[0]));
+       if (unlikely(!input)) {
+               local_irq_restore(flags);
                return -EINVAL;
        }
 
-       local_irq_save(flags);
-       input = *this_cpu_ptr(hyperv_pcpu_input_arg);
-
-       if (unlikely(!input)) {
+       if (count > batch_size) {
+               pr_err("Hyper-V: GPA count:%d exceeds supported:%u\n", count,
+                      batch_size);
                local_irq_restore(flags);
                return -EINVAL;
        }
 
        input->partition_id = HV_PARTITION_ID_SELF;
        input->host_visibility = visibility;
-       input->reserved0 = 0;
-       input->reserved1 = 0;
        memcpy((void *)input->gpa_page_list, pfn, count * sizeof(*pfn));
        hv_status = hv_do_rep_hypercall(
                        HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY, count,
diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c
index 1f7c3082a36d..7d143826e5dc 100644
--- a/arch/x86/hyperv/mmu.c
+++ b/arch/x86/hyperv/mmu.c
@@ -72,7 +72,7 @@ static void hyperv_flush_tlb_multi(const struct cpumask *cpus,
 
        local_irq_save(flags);
 
-       flush = *this_cpu_ptr(hyperv_pcpu_input_arg);
+       max_gvas = hv_hvcall_in_array(&flush, sizeof(*flush), 
sizeof(flush->gva_list[0]));
 
        if (unlikely(!flush)) {
                local_irq_restore(flags);
@@ -86,13 +86,10 @@ static void hyperv_flush_tlb_multi(const struct cpumask 
*cpus,
                 */
                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 {
@@ -139,8 +136,6 @@ static void hyperv_flush_tlb_multi(const struct cpumask 
*cpus,
         * 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,
@@ -179,7 +174,7 @@ static u64 hyperv_flush_tlb_others_ex(const struct cpumask 
*cpus,
        if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
                return HV_STATUS_INVALID_PARAMETER;
 
-       flush = *this_cpu_ptr(hyperv_pcpu_input_arg);
+       max_gvas = hv_hvcall_in_array(&flush, sizeof(*flush), 
sizeof(flush->gva_list[0]));
 
        if (info->mm) {
                /*
@@ -188,14 +183,10 @@ static u64 hyperv_flush_tlb_others_ex(const struct 
cpumask *cpus,
                 */
                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);
@@ -206,10 +197,10 @@ static u64 hyperv_flush_tlb_others_ex(const struct 
cpumask *cpus,
         * 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])) /
+       max_gvas -= (nr_bank * sizeof(flush->hv_vp_set.bank_contents[0])) /
                sizeof(flush->gva_list[0]);
+       if (max_gvas <= 0)
+               return HV_STATUS_INVALID_PARAMETER;
 
        if (info->end == TLB_FLUSH_ALL) {
                flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
diff --git a/arch/x86/hyperv/nested.c b/arch/x86/hyperv/nested.c
index 1083dc8646f9..88c39ac8d0aa 100644
--- a/arch/x86/hyperv/nested.c
+++ b/arch/x86/hyperv/nested.c
@@ -29,15 +29,13 @@ int hyperv_flush_guest_mapping(u64 as)
 
        local_irq_save(flags);
 
-       flush = *this_cpu_ptr(hyperv_pcpu_input_arg);
-
+       hv_hvcall_in(&flush, sizeof(*flush));
        if (unlikely(!flush)) {
                local_irq_restore(flags);
                goto fault;
        }
 
        flush->address_space = as;
-       flush->flags = 0;
 
        status = hv_do_hypercall(HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE,
                                 flush, NULL);
@@ -90,25 +88,23 @@ int hyperv_flush_guest_mapping_range(u64 as,
        u64 status;
        unsigned long flags;
        int ret = -ENOTSUPP;
-       int gpa_n = 0;
+       int batch_size, gpa_n = 0;
 
        if (!hv_hypercall_pg || !fill_flush_list_func)
                goto fault;
 
        local_irq_save(flags);
 
-       flush = *this_cpu_ptr(hyperv_pcpu_input_arg);
-
+       batch_size = hv_hvcall_in_array(&flush, sizeof(*flush),
+                                       sizeof(flush->gpa_list[0]));
        if (unlikely(!flush)) {
                local_irq_restore(flags);
                goto fault;
        }
 
        flush->address_space = as;
-       flush->flags = 0;
-
        gpa_n = fill_flush_list_func(flush, data);
-       if (gpa_n < 0) {
+       if (gpa_n < 0 || gpa_n > batch_size) {
                local_irq_restore(flags);
                goto fault;
        }
diff --git a/include/hyperv/hvgdk_mini.h b/include/hyperv/hvgdk_mini.h
index 58895883f636..70e5d7ee40c8 100644
--- a/include/hyperv/hvgdk_mini.h
+++ b/include/hyperv/hvgdk_mini.h
@@ -533,7 +533,7 @@ union hv_gpa_page_range {
 struct hv_guest_mapping_flush_list {
        u64 address_space;
        u64 flags;
-       union hv_gpa_page_range gpa_list[HV_MAX_FLUSH_REP_COUNT];
+       union hv_gpa_page_range gpa_list[];
 };
 
 struct hv_tlb_flush {   /* HV_INPUT_FLUSH_VIRTUAL_ADDRESS_LIST */
@@ -1218,7 +1218,7 @@ struct hv_gpa_range_for_visibility {
        u32 host_visibility : 2;
        u32 reserved0 : 30;
        u32 reserved1;
-       u64 gpa_page_list[HV_MAX_MODIFY_GPA_REP_COUNT];
+       u64 gpa_page_list[];
 } __packed;
 
 #if defined(CONFIG_X86)
-- 
2.25.1


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