[PATCH v7 5/8] KVM: selftests: Add helper for checking if running on powerpc pseries LPAR
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REVIEWED: 1 (0M)
From: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Date: 2026-10-06 10:30:12
Also in:
kvm, lkml
Subsystem:
kernel selftest framework, kernel virtual machine (kvm), the rest · Maintainers:
Shuah Khan, Shuah Khan, Paolo Bonzini, Linus Torvalds
Revision v7 of 4 in this series; 1 review trailer.
Revisions (4)
- v3 [diff vs current]
- v5 [diff vs current]
- v6 [diff vs current]
- v7 current
PowerPC's PAPR L0 does not guarantee H_GUEST_CREATE/H_GUEST_CREATE_VCPU hcalls to create upto MAX_VCPUS or hundreds of VMs, this is due to limited resouces at L0 for guest management space. This helper allows us to skip such tests which creates a lot of VMs/VCPUs, when we are running nested. Note that there is no easy way to differentiate between running nested on PowerNV v/s kvm-on-powervm case. So we use a common helper to detect any nested case. The helper is added to the common kvm_util header file to avoid sprinkling multiple #ifdef __powerpc64__ everywhere. Suggested-by: Sean Christopherson <seanjc@google.com> Tested-by: Anushree Mathur <redacted> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> --- tools/testing/selftests/kvm/include/kvm_util.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 9df16c8dc82a..258ae5879a5e 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h@@ -14,6 +14,7 @@ #include <linux/kvm.h> #include "linux/rbtree.h" #include <linux/types.h> +#include <unistd.h> #include <asm/atomic.h> #include <asm/kvm.h>
@@ -1063,6 +1064,22 @@ const char *exit_reason_str(unsigned int exit_reason); bool kvm_arch_needs_naturally_aligned_page_tables(void); +/* + * True on powerpc when this host is a pseries LPAR (nested case). + * PowerPC's PAPR L0 does not guarantee H_GUEST_CREATE / H_GUEST_CREATE_VCPU up + * to MAX_VCPUS or creating hundreds of VMs - due to limited resouces at L0 for + * guest management space. This helper allows us to skip such tests when we are + * running nested. + */ +static inline bool kvm_is_ppc_pseries_lpar(void) +{ +#ifdef __powerpc64__ + return !access("/proc/device-tree/rtas/ibm,hypertas-functions", F_OK); +#else + return false; +#endif +} + gpa_t ____vm_phy_pages_alloc(struct kvm_vm *vm, size_t nr_pages, gpa_t min_gpa, u32 memslot, bool protected, bool naturally_aligned); gpa_t __vm_phy_pages_alloc(struct kvm_vm *vm, size_t nr_pages,
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2.39.5