[PATCH 27/41] Drivers: hv: Make portions of Hyper-V init code be arch neutral
Tim Gardner
tim.gardner at canonical.com
Thu Nov 4 12:54:35 UTC 2021
From: Michael Kelley <mikelley at microsoft.com>
BugLink: https://bugs.launchpad.net/bugs/1949770
The code to allocate and initialize the hv_vp_index array is
architecture neutral. Similarly, the code to allocate and
populate the hypercall input and output arg pages is architecture
neutral. Move both sets of code out from arch/x86 and into
utility functions in drivers/hv/hv_common.c that can be shared
by Hyper-V initialization on ARM64.
No functional changes. However, the allocation of the hypercall
input and output arg pages is done differently so that the
size is always the Hyper-V page size, even if not the same as
the guest page size (such as with ARM64's 64K page size).
Signed-off-by: Michael Kelley <mikelley at microsoft.com>
Link: https://lore.kernel.org/r/1626287687-2045-2-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu at kernel.org>
(backported from commit afca4d95dd7d7936d46a0ff02169cc40f534a6a3)
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
[rtg - minor conflict adjustments. Dropped duplicate definitions of
hyperv_pcpu_input_arg, hv_max_vp_index, and hv_vp_index in
arch/arm64/hyperv/mshyperv.c]
---
arch/arm64/hyperv/mshyperv.c | 9 ---
arch/x86/hyperv/hv_init.c | 66 +++-------------
arch/x86/kernel/cpu/mshyperv.c | 3 -
drivers/hv/hv_common.c | 138 +++++++++++++++++++++++++++++++++
include/asm-generic/mshyperv.h | 8 ++
5 files changed, 156 insertions(+), 68 deletions(-)
diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c
index 95f7e4ef3033..1748f99ca65b 100644
--- a/arch/arm64/hyperv/mshyperv.c
+++ b/arch/arm64/hyperv/mshyperv.c
@@ -29,15 +29,6 @@ EXPORT_SYMBOL_GPL(ms_hyperv);
bool hv_root_partition;
EXPORT_SYMBOL_GPL(hv_root_partition);
-u32 *hv_vp_index;
-EXPORT_SYMBOL_GPL(hv_vp_index);
-
-u32 hv_max_vp_index;
-EXPORT_SYMBOL_GPL(hv_max_vp_index);
-
-void __percpu **hyperv_pcpu_input_arg;
-EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
-
static int hv_cpu_init(unsigned int cpu)
{
void **input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index b952e7d38459..08284bfca479 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -43,38 +43,17 @@ EXPORT_SYMBOL_GPL(hv_hypercall_pg);
/* Storage to save the hypercall page temporarily for hibernation */
static void *hv_hypercall_pg_saved;
-u32 *hv_vp_index;
-EXPORT_SYMBOL_GPL(hv_vp_index);
-
struct hv_vp_assist_page **hv_vp_assist_page;
EXPORT_SYMBOL_GPL(hv_vp_assist_page);
-void __percpu **hyperv_pcpu_input_arg;
-EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
-
-u32 hv_max_vp_index;
-EXPORT_SYMBOL_GPL(hv_max_vp_index);
-
static int hv_cpu_init(unsigned int cpu)
{
- u64 msr_vp_index;
struct hv_vp_assist_page **hvp = &hv_vp_assist_page[smp_processor_id()];
- 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);
- if (unlikely(!pg))
- return -ENOMEM;
- *input_arg = page_address(pg);
-
- msr_vp_index = hv_get_register(HV_REGISTER_VP_INDEX);
-
- hv_vp_index[smp_processor_id()] = msr_vp_index;
+ int ret;
- if (msr_vp_index > hv_max_vp_index)
- hv_max_vp_index = msr_vp_index;
+ ret = hv_common_cpu_init(cpu);
+ if (ret)
+ return ret;
if (!hv_vp_assist_page)
return 0;
@@ -192,16 +171,8 @@ static int hv_cpu_die(unsigned int cpu)
{
struct hv_reenlightenment_control re_ctrl;
unsigned int new_cpu;
- unsigned long flags;
- void **input_arg;
- void *input_pg = NULL;
- local_irq_save(flags);
- input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
- input_pg = *input_arg;
- *input_arg = NULL;
- local_irq_restore(flags);
- free_page((unsigned long)input_pg);
+ hv_common_cpu_die(cpu);
if (hv_vp_assist_page && hv_vp_assist_page[cpu])
wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, 0);
@@ -332,7 +303,7 @@ void __init hyperv_init(void)
{
u64 guest_id, required_msrs;
union hv_x64_msr_hypercall_contents hypercall_msr;
- int cpuhp, i;
+ int cpuhp;
if (x86_hyper_type != X86_HYPER_MS_HYPERV)
return;
@@ -344,30 +315,14 @@ void __init hyperv_init(void)
if ((ms_hyperv.features & required_msrs) != required_msrs)
return;
- /*
- * Allocate the per-CPU state for the hypercall input arg.
- * If this allocation fails, we will not be able to setup
- * (per-CPU) hypercall input page and thus this failure is
- * fatal on Hyper-V.
- */
- hyperv_pcpu_input_arg = alloc_percpu(void *);
-
- BUG_ON(hyperv_pcpu_input_arg == NULL);
-
- /* Allocate percpu VP index */
- hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
- GFP_KERNEL);
- if (!hv_vp_index)
+ if (hv_common_init())
return;
- for (i = 0; i < num_possible_cpus(); i++)
- hv_vp_index[i] = VP_INVAL;
-
hv_vp_assist_page = kcalloc(num_possible_cpus(),
sizeof(*hv_vp_assist_page), GFP_KERNEL);
if (!hv_vp_assist_page) {
ms_hyperv.hints &= ~HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
- goto free_vp_index;
+ goto common_free;
}
cpuhp = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv_init:online",
@@ -424,9 +379,8 @@ void __init hyperv_init(void)
free_vp_assist_page:
kfree(hv_vp_assist_page);
hv_vp_assist_page = NULL;
-free_vp_index:
- kfree(hv_vp_index);
- hv_vp_index = NULL;
+common_free:
+ hv_common_free();
}
/*
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 654ec4412161..ea7091596d73 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -34,10 +34,7 @@
/* Is Linux running as the root partition? */
bool hv_root_partition;
-EXPORT_SYMBOL_GPL(hv_root_partition);
-
struct ms_hyperv_info ms_hyperv;
-EXPORT_SYMBOL_GPL(ms_hyperv);
#if IS_ENABLED(CONFIG_HYPERV)
static void (*vmbus_handler)(void);
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index f0053c786891..caba4f728987 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -15,9 +15,147 @@
#include <linux/types.h>
#include <linux/export.h>
#include <linux/bitfield.h>
+#include <linux/cpumask.h>
+#include <linux/slab.h>
#include <asm/hyperv-tlfs.h>
#include <asm/mshyperv.h>
+/*
+ * hv_root_partition and ms_hyperv are defined here with other Hyper-V
+ * specific globals so they are shared across all architectures and are
+ * built only when CONFIG_HYPERV is defined. But on x86,
+ * ms_hyperv_init_platform() is built even when CONFIG_HYPERV is not
+ * defined, and it uses these two variables. So mark them as __weak
+ * here, allowing for an overriding definition in the module containing
+ * ms_hyperv_init_platform().
+ */
+bool __weak hv_root_partition;
+EXPORT_SYMBOL_GPL(hv_root_partition);
+
+struct ms_hyperv_info __weak ms_hyperv;
+EXPORT_SYMBOL_GPL(ms_hyperv);
+
+u32 *hv_vp_index;
+EXPORT_SYMBOL_GPL(hv_vp_index);
+
+u32 hv_max_vp_index;
+EXPORT_SYMBOL_GPL(hv_max_vp_index);
+
+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);
+
+/*
+ * Hyper-V specific initialization and shutdown code that is
+ * common across all architectures. Called from architecture
+ * specific initialization functions.
+ */
+
+void __init hv_common_free(void)
+{
+ kfree(hv_vp_index);
+ hv_vp_index = NULL;
+
+ free_percpu(hyperv_pcpu_output_arg);
+ hyperv_pcpu_output_arg = NULL;
+
+ free_percpu(hyperv_pcpu_input_arg);
+ hyperv_pcpu_input_arg = NULL;
+}
+
+int __init hv_common_init(void)
+{
+ int i;
+
+ /*
+ * Allocate the per-CPU state for the hypercall input arg.
+ * If this allocation fails, we will not be able to setup
+ * (per-CPU) hypercall input page and thus this failure is
+ * fatal on Hyper-V.
+ */
+ hyperv_pcpu_input_arg = alloc_percpu(void *);
+ BUG_ON(!hyperv_pcpu_input_arg);
+
+ /* 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);
+ }
+
+ hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
+ GFP_KERNEL);
+ if (!hv_vp_index) {
+ hv_common_free();
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < num_possible_cpus(); i++)
+ hv_vp_index[i] = VP_INVAL;
+
+ return 0;
+}
+
+/*
+ * Hyper-V specific initialization and die code for
+ * individual CPUs that is common across all architectures.
+ * Called by the CPU hotplug mechanism.
+ */
+
+int hv_common_cpu_init(unsigned int cpu)
+{
+ void **inputarg, **outputarg;
+ u64 msr_vp_index;
+ gfp_t flags;
+ int pgcount = hv_root_partition ? 2 : 1;
+
+ /* hv_cpu_init() can be called with IRQs disabled from hv_resume() */
+ flags = irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL;
+
+ inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
+ *inputarg = kmalloc(pgcount * HV_HYP_PAGE_SIZE, flags);
+ if (!(*inputarg))
+ return -ENOMEM;
+
+ if (hv_root_partition) {
+ outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
+ *outputarg = (char *)(*inputarg) + HV_HYP_PAGE_SIZE;
+ }
+
+ msr_vp_index = hv_get_register(HV_REGISTER_VP_INDEX);
+
+ hv_vp_index[cpu] = msr_vp_index;
+
+ if (msr_vp_index > hv_max_vp_index)
+ hv_max_vp_index = msr_vp_index;
+
+ return 0;
+}
+
+int hv_common_cpu_die(unsigned int cpu)
+{
+ unsigned long flags;
+ void **inputarg, **outputarg;
+ void *mem;
+
+ local_irq_save(flags);
+
+ inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
+ mem = *inputarg;
+ *inputarg = NULL;
+
+ if (hv_root_partition) {
+ outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
+ *outputarg = NULL;
+ }
+
+ local_irq_restore(flags);
+
+ kfree(mem);
+
+ return 0;
+}
/* Bit mask of the extended capability to query: see HV_EXT_CAPABILITY_xxx */
bool hv_query_ext_cap(u64 cap_query)
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index bd79b48cfe07..f5fd88eedaed 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -37,6 +37,9 @@ struct ms_hyperv_info {
};
extern struct ms_hyperv_info ms_hyperv;
+extern void __percpu **hyperv_pcpu_input_arg;
+extern void __percpu **hyperv_pcpu_output_arg;
+
extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
@@ -165,6 +168,11 @@ extern void __percpu **hyperv_pcpu_input_arg;
/* Sentinel value for an uninitialized entry in hv_vp_index array */
#define VP_INVAL U32_MAX
+int __init hv_common_init(void);
+void __init hv_common_free(void);
+int hv_common_cpu_init(unsigned int cpu);
+int hv_common_cpu_die(unsigned int cpu);
+
void *hv_alloc_hyperv_page(void);
void *hv_alloc_hyperv_zeroed_page(void);
void hv_free_hyperv_page(unsigned long addr);
--
2.33.1
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