From: Nuno Das Neves <nudasnev@xxxxxxxxxxxxx>
Move hv_current_partition_id and hv_get_partition_id() to hv_common.c.
These aren't specific to x86_64 and will be needed by common code.
Set hv_current_partition_id to HV_PARTITION_ID_SELF by default.
Use a stack variable for the output of the hypercall. This allows moving
the call of hv_get_partition_id() to hv_common_init() before the percpu
pages are initialized.
Remove the BUG()s. Failing to get the id need not crash the machine.
Signed-off-by: Nuno Das Neves <nudasnev@xxxxxxxxxxxxx>
---
arch/x86/hyperv/hv_init.c | 26 --------------------------
arch/x86/include/asm/mshyperv.h | 2 --
drivers/hv/hv_common.c | 23 +++++++++++++++++++++++
include/asm-generic/mshyperv.h | 1 +
4 files changed, 24 insertions(+), 28 deletions(-)
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 173005e6a95d..6b9f6f9f704d 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -34,9 +34,6 @@
#include <clocksource/hyperv_timer.h>
#include <linux/highmem.h>
-u64 hv_current_partition_id = ~0ull;
-EXPORT_SYMBOL_GPL(hv_current_partition_id);
-
void *hv_hypercall_pg;
EXPORT_SYMBOL_GPL(hv_hypercall_pg);
@@ -393,24 +390,6 @@ static void __init hv_stimer_setup_percpu_clockev(void)
old_setup_percpu_clockev();
}
-static void __init hv_get_partition_id(void)
-{
- struct hv_get_partition_id *output_page;
- u64 status;
- unsigned long flags;
-
- local_irq_save(flags);
- output_page = *this_cpu_ptr(hyperv_pcpu_output_arg);
- status = hv_do_hypercall(HVCALL_GET_PARTITION_ID, NULL, output_page);
- if (!hv_result_success(status)) {
- /* No point in proceeding if this failed */
- pr_err("Failed to get partition ID: %lld\n", status);
- BUG();
- }
- hv_current_partition_id = output_page->partition_id;
- local_irq_restore(flags);
-}
-
#if IS_ENABLED(CONFIG_HYPERV_VTL_MODE)
static u8 __init get_vtl(void)
{
@@ -605,11 +584,6 @@ void __init hyperv_init(void)
register_syscore_ops(&hv_syscore_ops);
- if (cpuid_ebx(HYPERV_CPUID_FEATURES) & HV_ACCESS_PARTITION_ID)
- hv_get_partition_id();
-
- BUG_ON(hv_root_partition && hv_current_partition_id == ~0ull);
-
#ifdef CONFIG_PCI_MSI
/*
* If we're running as root, we want to create our own PCI MSI domain.
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index f91ab1e75f9f..8d3ada3e8d0d 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -43,8 +43,6 @@ extern bool hyperv_paravisor_present;
extern void *hv_hypercall_pg;
-extern u64 hv_current_partition_id;
-
extern union hv_ghcb * __percpu *hv_ghcb_pg;
bool hv_isolation_type_snp(void);
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index af5d1dc451f6..1da19b64ef16 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -31,6 +31,9 @@
#include <hyperv/hvhdk.h>
#include <asm/mshyperv.h>
+u64 hv_current_partition_id = HV_PARTITION_ID_SELF;
+EXPORT_SYMBOL_GPL(hv_current_partition_id);
+
/*
* hv_root_partition, ms_hyperv and hv_nested are defined here with other
* Hyper-V specific globals so they are shared across all architectures and are
@@ -283,6 +286,23 @@ static inline bool hv_output_page_exists(void)
return hv_root_partition || IS_ENABLED(CONFIG_HYPERV_VTL_MODE);
}
+static void __init hv_get_partition_id(void)
+{
+ /*
+ * Note in this case the output can be on the stack because it is just
+ * a single u64 and hence won't cross a page boundary.
+ */
+ struct hv_get_partition_id output;
+ u64 status;
+
+ status = hv_do_hypercall(HVCALL_GET_PARTITION_ID, NULL, &output);
+ if (!hv_result_success(status)) {
+ pr_err("Hyper-V: failed to get partition ID: %#lx\n", status);
+ return;
+ }
+ hv_current_partition_id = output.partition_id;
+}
+
int __init hv_common_init(void)
{
int i;
@@ -298,6 +318,9 @@ int __init hv_common_init(void)
if (hv_is_isolation_supported())
sysctl_record_panic_msg = 0;
+ if (ms_hyperv.priv_high & HV_ACCESS_PARTITION_ID)
+ hv_get_partition_id();
+
/*
* Hyper-V expects to get crash register data or kmsg when
* crash enlightment is available and system crashes. Set
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index a7bbe504e4f3..98100466e0b2 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -58,6 +58,7 @@ struct ms_hyperv_info {
};
extern struct ms_hyperv_info ms_hyperv;
extern bool hv_nested;
+extern u64 hv_current_partition_id;
extern void * __percpu *hyperv_pcpu_input_arg;
extern void * __percpu *hyperv_pcpu_output_arg;
--
2.34.1
