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authorLinus Torvalds <torvalds@linux-foundation.org>2023-11-22 09:56:26 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2023-11-22 09:56:26 -0800
commit05c8c94ed407499279b2a552e7ee9bb03e859b7b (patch)
tree45baf7c954fce18cb2ebb0345ba37379af81a58b /arch
parent125b0bb95dd6bec81b806b997a4ccb026eeecf8f (diff)
parent18286883e779fb79b413a7462968ee3f6768f19c (diff)
Merge tag 'hyperv-fixes-signed-20231121' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv fixes from Wei Liu: - One fix for the KVP daemon (Ani Sinha) - Fix for the detection of E820_TYPE_PRAM in a Gen2 VM (Saurabh Sengar) - Micro-optimization for hv_nmi_unknown() (Uros Bizjak) * tag 'hyperv-fixes-signed-20231121' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Use atomic_try_cmpxchg() to micro-optimize hv_nmi_unknown() x86/hyperv: Fix the detection of E820_TYPE_PRAM in a Gen2 VM hv/hv_kvp_daemon: Some small fixes for handling NM keyfiles
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/hyperv/hv_init.c25
-rw-r--r--arch/x86/kernel/cpu/mshyperv.c5
2 files changed, 25 insertions, 5 deletions
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 21556ad87f4b..8f3a4d16bb79 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -15,6 +15,7 @@
#include <linux/io.h>
#include <asm/apic.h>
#include <asm/desc.h>
+#include <asm/e820/api.h>
#include <asm/sev.h>
#include <asm/ibt.h>
#include <asm/hypervisor.h>
@@ -286,15 +287,31 @@ static int hv_cpu_die(unsigned int cpu)
static int __init hv_pci_init(void)
{
- int gen2vm = efi_enabled(EFI_BOOT);
+ bool gen2vm = efi_enabled(EFI_BOOT);
/*
- * For Generation-2 VM, we exit from pci_arch_init() by returning 0.
- * The purpose is to suppress the harmless warning:
+ * A Generation-2 VM doesn't support legacy PCI/PCIe, so both
+ * raw_pci_ops and raw_pci_ext_ops are NULL, and pci_subsys_init() ->
+ * pcibios_init() doesn't call pcibios_resource_survey() ->
+ * e820__reserve_resources_late(); as a result, any emulated persistent
+ * memory of E820_TYPE_PRAM (12) via the kernel parameter
+ * memmap=nn[KMG]!ss is not added into iomem_resource and hence can't be
+ * detected by register_e820_pmem(). Fix this by directly calling
+ * e820__reserve_resources_late() here: e820__reserve_resources_late()
+ * depends on e820__reserve_resources(), which has been called earlier
+ * from setup_arch(). Note: e820__reserve_resources_late() also adds
+ * any memory of E820_TYPE_PMEM (7) into iomem_resource, and
+ * acpi_nfit_register_region() -> acpi_nfit_insert_resource() ->
+ * region_intersects() returns REGION_INTERSECTS, so the memory of
+ * E820_TYPE_PMEM won't get added twice.
+ *
+ * We return 0 here so that pci_arch_init() won't print the warning:
* "PCI: Fatal: No config space access function found"
*/
- if (gen2vm)
+ if (gen2vm) {
+ e820__reserve_resources_late();
return 0;
+ }
/* For Generation-1 VM, we'll proceed in pci_arch_init(). */
return 1;
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index e6bba12c759c..01fa06dd06b6 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -262,11 +262,14 @@ static uint32_t __init ms_hyperv_platform(void)
static int hv_nmi_unknown(unsigned int val, struct pt_regs *regs)
{
static atomic_t nmi_cpu = ATOMIC_INIT(-1);
+ unsigned int old_cpu, this_cpu;
if (!unknown_nmi_panic)
return NMI_DONE;
- if (atomic_cmpxchg(&nmi_cpu, -1, raw_smp_processor_id()) != -1)
+ old_cpu = -1;
+ this_cpu = raw_smp_processor_id();
+ if (!atomic_try_cmpxchg(&nmi_cpu, &old_cpu, this_cpu))
return NMI_HANDLED;
return NMI_DONE;