diff mbox series

[3/7] x86/hyperv: Use hv_hvcall_*() to set up hypercall arguments -- part 1

Message ID 20250226200612.2062-4-mhklinux@outlook.com (mailing list archive)
State Handled Elsewhere
Delegated to: Krzysztof WilczyƄski
Headers show
Series hyperv: Introduce new way to manage hypercall args | expand

Commit Message

Michael Kelley Feb. 26, 2025, 8:06 p.m. UTC
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>
---
 arch/x86/hyperv/hv_apic.c   |  6 ++----
 arch/x86/hyperv/hv_init.c   |  5 +----
 arch/x86/hyperv/hv_vtl.c    |  8 ++------
 arch/x86/hyperv/irqdomain.c | 10 ++++------
 4 files changed, 9 insertions(+), 20 deletions(-)

Comments

Nuno Das Neves Feb. 27, 2025, 9:07 p.m. UTC | #1
On 2/26/2025 12:06 PM, mhkelley58@gmail.com wrote:
> 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>
> ---
>  arch/x86/hyperv/hv_apic.c   |  6 ++----
>  arch/x86/hyperv/hv_init.c   |  5 +----
>  arch/x86/hyperv/hv_vtl.c    |  8 ++------
>  arch/x86/hyperv/irqdomain.c | 10 ++++------
>  4 files changed, 9 insertions(+), 20 deletions(-)
> 
> diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
> index f022d5f64fb6..c16f81dd36fc 100644
> --- a/arch/x86/hyperv/hv_apic.c
> +++ b/arch/x86/hyperv/hv_apic.c
> @@ -115,14 +115,12 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector,
>  		return false;
>  
>  	local_irq_save(flags);
> -	ipi_arg = *this_cpu_ptr(hyperv_pcpu_input_arg);
> -
> +	hv_hvcall_in_array(&ipi_arg, sizeof(*ipi_arg),
> +				sizeof(ipi_arg->vp_set.bank_contents[0]));
I think the returned "batch size" should be checked to ensure it is not too small to hold the
variable-sized part of the header.

>  	if (unlikely(!ipi_arg))
>  		goto ipi_mask_ex_done;
>  
While here, is this check really needed? If so, maybe a check for the percpu page(s) could be
baked into hv_hvcall_inout_array()?

>  	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
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index ddeb40930bc8..c5c9511cb7ed 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -400,13 +400,10 @@ 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(&input, sizeof(*input), &output, sizeof(*output));

This doesn't look right, this is a rep hypercall taking an array of register names
and outputting an array of register values.

hv_hvcall_inout_array() should be fully utilized (input and output arrays) here.

The current code may actually work, but it will overlap the input and output!

>  	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..3dd27d548db6 100644
> --- a/arch/x86/hyperv/hv_vtl.c
> +++ b/arch/x86/hyperv/hv_vtl.c
<snip>
> @@ -185,13 +184,10 @@ 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(&input, sizeof(*input), &output, sizeof(*output));
This has the same issue as above - it is a rep hypercall so needs hv_hvcall_inout_array()

>  	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..803b1a945c5c 100644
> --- a/arch/x86/hyperv/irqdomain.c
> +++ b/arch/x86/hyperv/irqdomain.c
> @@ -24,11 +24,11 @@ static int hv_map_interrupt(union hv_device_id device_id, bool level,
>  
>  	local_irq_save(flags);
>  
> -	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
> -	output = *this_cpu_ptr(hyperv_pcpu_output_arg);
> +	hv_hvcall_inout_array(&input, sizeof(*input),
> +			sizeof(input->interrupt_descriptor.target.vp_set.bank_contents[0]),
> +			&output, sizeof(*output), 0);
As noted before I think the batch size should be checked to ensure it is large enough.

Side note - it seems in this hypercall, nr_banks + 1 is used as the varhead size, which
counts the vp valid mask, but this is not the case in __send_ipi_mask_ex(). Do you happen
to know why that might be?

Thanks,
Nuno

>  
>  	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;
<snip>
diff mbox series

Patch

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index f022d5f64fb6..c16f81dd36fc 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -115,14 +115,12 @@  static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector,
 		return false;
 
 	local_irq_save(flags);
-	ipi_arg = *this_cpu_ptr(hyperv_pcpu_input_arg);
-
+	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
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index ddeb40930bc8..c5c9511cb7ed 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -400,13 +400,10 @@  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(&input, sizeof(*input), &output, sizeof(*output));
 	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..3dd27d548db6 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 +184,10 @@  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(&input, sizeof(*input), &output, 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..803b1a945c5c 100644
--- a/arch/x86/hyperv/irqdomain.c
+++ b/arch/x86/hyperv/irqdomain.c
@@ -24,11 +24,11 @@  static int hv_map_interrupt(union hv_device_id device_id, bool level,
 
 	local_irq_save(flags);
 
-	input = *this_cpu_ptr(hyperv_pcpu_input_arg);
-	output = *this_cpu_ptr(hyperv_pcpu_output_arg);
+	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) {
@@ -77,9 +76,8 @@  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;