[PATCH v2 2/6] x86/hyperv: Use hv_hvcall_*() to set up hypercall arguments -- part 1

[mhkelley58@gmail.com]

From: Michael Kelley <mhklinux@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.

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

Notes:
    Changes in v2:
    * Fixed get_vtl() and hv_vtl_apicid_to_vp_id() to properly treat the input
      and output arguments as arrays [Nuno Das Neves]
    * Enhanced __send_ipi_mask_ex() and hv_map_interrupt() to check the number
      of computed banks in the hv_vpset against the batch_size. 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/hv_apic.c   | 10 ++++------
 arch/x86/hyperv/hv_init.c   |  6 ++----
 arch/x86/hyperv/hv_vtl.c    |  9 +++------
 arch/x86/hyperv/irqdomain.c | 17 ++++++++++-------
 4 files changed, 19 insertions(+), 23 deletions(-)

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index f022d5f64fb6..b5d6a9b2e17a 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -108,21 +108,19 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector,
 {
 	struct hv_send_ipi_ex *ipi_arg;
 	unsigned long flags;
-	int nr_bank = 0;
+	int batch_size, nr_bank = 0;
 	u64 status = HV_STATUS_INVALID_PARAMETER;
 
 	if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
 		return false;
 
 	local_irq_save(flags);
-	ipi_arg = *this_cpu_ptr(hyperv_pcpu_input_arg);
-
+	batch_size = hv_hvcall_in_array(&ipi_arg, sizeof(*ipi_arg),
+					sizeof(ipi_arg->vp_set.bank_contents[0]));
 	if (unlikely(!ipi_arg))
 		goto ipi_mask_ex_done;
 
 	ipi_arg->vector = vector;
-	ipi_arg->reserved = 0;
-	ipi_arg->vp_set.valid_bank_mask = 0;
 
 	/*
 	 * Use HV_GENERIC_SET_ALL and avoid converting cpumask to VP_SET
@@ -139,7 +137,7 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector,
 		 * represented in VP_SET. Return an error and fall back to
 		 * native (architectural) method of sending IPIs.
 		 */
-		if (nr_bank <= 0)
+		if (nr_bank <= 0 || nr_bank > batch_size)
 			goto ipi_mask_ex_done;
 	} else {
 		ipi_arg->vp_set.format = HV_GENERIC_SET_ALL;
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index ddeb40930bc8..cc843905c23a 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -400,13 +400,11 @@ static u8 __init get_vtl(void)
 	u64 ret;
 
 	local_irq_save(flags);
-	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
-	output = *this_cpu_ptr(hyperv_pcpu_output_arg);
 
-	memset(input, 0, struct_size(input, names, 1));
+	hv_hvcall_inout_array(&input, sizeof(*input), sizeof(input->names[0]),
+			      &output, sizeof(*output), sizeof(output->values[0]));
 	input->partition_id = HV_PARTITION_ID_SELF;
 	input->vp_index = HV_VP_INDEX_SELF;
-	input->input_vtl.as_uint8 = 0;
 	input->names[0] = HV_REGISTER_VSM_VP_STATUS;
 
 	ret = hv_do_hypercall(control, input, output);
diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c
index 3f4e20d7b724..5d9aaebe5709 100644
--- a/arch/x86/hyperv/hv_vtl.c
+++ b/arch/x86/hyperv/hv_vtl.c
@@ -94,8 +94,7 @@ static int hv_vtl_bringup_vcpu(u32 target_vp_index, int cpu, u64 eip_ignored)
 
 	local_irq_save(irq_flags);
 
-	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
-	memset(input, 0, sizeof(*input));
+	hv_hvcall_in(&input, sizeof(*input));
 
 	input->partition_id = HV_PARTITION_ID_SELF;
 	input->vp_index = target_vp_index;
@@ -185,13 +184,11 @@ static int hv_vtl_apicid_to_vp_id(u32 apic_id)
 
 	local_irq_save(irq_flags);
 
-	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
-	memset(input, 0, sizeof(*input));
+	hv_hvcall_inout_array(&input, sizeof(*input), sizeof(input->apic_ids[0]),
+			      &output, 0, sizeof(*output));
 	input->partition_id = HV_PARTITION_ID_SELF;
 	input->apic_ids[0] = apic_id;
 
-	output = *this_cpu_ptr(hyperv_pcpu_output_arg);
-
 	control = HV_HYPERCALL_REP_COMP_1 | HVCALL_GET_VP_ID_FROM_APIC_ID;
 	status = hv_do_hypercall(control, input, output);
 	ret = output[0];
diff --git a/arch/x86/hyperv/irqdomain.c b/arch/x86/hyperv/irqdomain.c
index 64b921360b0f..1f78b2ea7489 100644
--- a/arch/x86/hyperv/irqdomain.c
+++ b/arch/x86/hyperv/irqdomain.c
@@ -20,15 +20,15 @@ static int hv_map_interrupt(union hv_device_id device_id, bool level,
 	struct hv_device_interrupt_descriptor *intr_desc;
 	unsigned long flags;
 	u64 status;
-	int nr_bank, var_size;
+	int batch_size, nr_bank, var_size;
 
 	local_irq_save(flags);
 
-	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
-	output = *this_cpu_ptr(hyperv_pcpu_output_arg);
+	batch_size = hv_hvcall_inout_array(&input, sizeof(*input),
+			sizeof(input->interrupt_descriptor.target.vp_set.bank_contents[0]),
+			&output, sizeof(*output), 0);
 
 	intr_desc = &input->interrupt_descriptor;
-	memset(input, 0, sizeof(*input));
 	input->partition_id = hv_current_partition_id;
 	input->device_id = device_id.as_uint64;
 	intr_desc->interrupt_type = HV_X64_INTERRUPT_TYPE_FIXED;
@@ -40,7 +40,6 @@ static int hv_map_interrupt(union hv_device_id device_id, bool level,
 	else
 		intr_desc->trigger_mode = HV_INTERRUPT_TRIGGER_MODE_EDGE;
 
-	intr_desc->target.vp_set.valid_bank_mask = 0;
 	intr_desc->target.vp_set.format = HV_GENERIC_SET_SPARSE_4K;
 	nr_bank = cpumask_to_vpset(&(intr_desc->target.vp_set), cpumask_of(cpu));
 	if (nr_bank < 0) {
@@ -48,6 +47,11 @@ static int hv_map_interrupt(union hv_device_id device_id, bool level,
 		pr_err("%s: unable to generate VP set\n", __func__);
 		return EINVAL;
 	}
+	if (nr_bank > batch_size) {
+		local_irq_restore(flags);
+		pr_err("%s: nr_bank too large\n", __func__);
+		return EINVAL;
+	}
 	intr_desc->target.flags = HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET;
 
 	/*
@@ -77,9 +81,8 @@ static int hv_unmap_interrupt(u64 id, struct hv_interrupt_entry *old_entry)
 	u64 status;
 
 	local_irq_save(flags);
-	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
 
-	memset(input, 0, sizeof(*input));
+	hv_hvcall_in(&input, sizeof(*input));
 	intr_entry = &input->interrupt_entry;
 	input->partition_id = hv_current_partition_id;
 	input->device_id = id;
-- 
2.25.1