Commit 5d0f077e authored by Wei Liu's avatar Wei Liu
Browse files

x86/hyperv: allocate output arg pages if required



When Linux runs as the root partition, it will need to make hypercalls
which return data from the hypervisor.

Allocate pages for storing results when Linux runs as the root
partition.

Signed-off-by: default avatarLillian Grassin-Drake <ligrassi@microsoft.com>
Co-Developed-by: default avatarLillian Grassin-Drake <ligrassi@microsoft.com>
Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-6-wei.liu@kernel.org
parent 7d4163c8
......@@ -45,6 +45,9 @@ EXPORT_SYMBOL_GPL(hv_vp_assist_page);
void __percpu **hyperv_pcpu_input_arg;
EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
void __percpu **hyperv_pcpu_output_arg;
EXPORT_SYMBOL_GPL(hyperv_pcpu_output_arg);
u32 hv_max_vp_index;
EXPORT_SYMBOL_GPL(hv_max_vp_index);
......@@ -77,12 +80,19 @@ static int hv_cpu_init(unsigned int cpu)
void **input_arg;
struct page *pg;
input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
/* hv_cpu_init() can be called with IRQs disabled from hv_resume() */
pg = alloc_page(irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
pg = alloc_pages(irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL, hv_root_partition ? 1 : 0);
if (unlikely(!pg))
return -ENOMEM;
input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
*input_arg = page_address(pg);
if (hv_root_partition) {
void **output_arg;
output_arg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
*output_arg = page_address(pg + 1);
}
hv_get_vp_index(msr_vp_index);
......@@ -209,14 +219,23 @@ static int hv_cpu_die(unsigned int cpu)
unsigned int new_cpu;
unsigned long flags;
void **input_arg;
void *input_pg = NULL;
void *pg;
local_irq_save(flags);
input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
input_pg = *input_arg;
pg = *input_arg;
*input_arg = NULL;
if (hv_root_partition) {
void **output_arg;
output_arg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
*output_arg = NULL;
}
local_irq_restore(flags);
free_page((unsigned long)input_pg);
free_pages((unsigned long)pg, hv_root_partition ? 1 : 0);
if (hv_vp_assist_page && hv_vp_assist_page[cpu])
wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, 0);
......@@ -369,6 +388,12 @@ void __init hyperv_init(void)
BUG_ON(hyperv_pcpu_input_arg == NULL);
/* Allocate the per-CPU state for output arg for root */
if (hv_root_partition) {
hyperv_pcpu_output_arg = alloc_percpu(void *);
BUG_ON(hyperv_pcpu_output_arg == NULL);
}
/* Allocate percpu VP index */
hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
GFP_KERNEL);
......
......@@ -78,6 +78,7 @@ extern int hyperv_init_cpuhp;
extern void *hv_hypercall_pg;
extern void __percpu **hyperv_pcpu_input_arg;
extern void __percpu **hyperv_pcpu_output_arg;
static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
{
......
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