From 5d0f077e0f413b7eca827b16ea8bfc4569e3946c Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Wed, 3 Feb 2021 15:04:24 +0000 Subject: [PATCH] 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: Lillian Grassin-Drake Co-Developed-by: Lillian Grassin-Drake Signed-off-by: Wei Liu Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20210203150435.27941-6-wei.liu@kernel.org --- arch/x86/hyperv/hv_init.c | 35 ++++++++++++++++++++++++++++----- arch/x86/include/asm/mshyperv.h | 1 + 2 files changed, 31 insertions(+), 5 deletions(-) diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index 6608d50d7aaa4..a73f4db318706 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -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); diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 4014a1ca2faea..ef06cdac8444d 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -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) {