[PATCH 53/60] kvm: x86: Introduce max_planes x86-op
From: Jörg Rödel <joro@8bytes.org>
Date: 2026-06-08 14:43:29
Also in:
kvm, kvm-riscv, kvmarm, linux-mips, lkml, loongarch
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Paolo Bonzini <pbonzini@redhat.com> Allow x86 hardware backends to overwrite the number of supported planes per VM type. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Co-developed-by: Joerg Roedel <redacted> Signed-off-by: Joerg Roedel <redacted> --- arch/x86/include/asm/kvm-x86-ops.h | 1 + arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/svm/svm.c | 1 + arch/x86/kvm/vmx/main.c | 1 + arch/x86/kvm/x86.c | 8 +++++++- arch/x86/kvm/x86.h | 1 + 6 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 207d56d12459..4f96090c04c9 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h@@ -152,6 +152,7 @@ KVM_X86_OP_OPTIONAL_RET0(gmem_max_mapping_level) KVM_X86_OP_OPTIONAL(gmem_invalidate) KVM_X86_OP(alloc_plane) KVM_X86_OP(free_plane) +KVM_X86_OP(max_planes) #endif #undef KVM_X86_OP
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 1b7aa48c961e..bfa0188d372f 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h@@ -2016,6 +2016,8 @@ struct kvm_x86_ops { struct kvm_plane *(*alloc_plane)(void); void (*free_plane)(struct kvm_plane *); + + unsigned (*max_planes)(struct kvm *); }; struct kvm_x86_nested_ops {
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 2a92d8d18d7c..99357de14034 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c@@ -5448,6 +5448,7 @@ struct kvm_x86_ops svm_x86_ops __initdata = { .alloc_plane = x86_alloc_plane, .free_plane = x86_free_plane, + .max_planes = kvm_x86_default_max_planes, }; /*
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index a2fc4eeeca1d..572921bdfb32 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c@@ -1034,6 +1034,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = { .alloc_plane = x86_alloc_plane, .free_plane = x86_free_plane, + .max_planes = kvm_x86_default_max_planes, }; struct kvm_x86_init_ops vt_init_ops __initdata = {
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 60b34bd4da9d..c6910356b061 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c@@ -482,10 +482,16 @@ static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all_except_vmx) + (KVM_LAST_EMULATED_VMX_MSR - KVM_FIRST_EMULATED_VMX_MSR + 1)]; static unsigned int num_msr_based_features; -unsigned kvm_arch_max_planes(struct kvm *kvm) +unsigned kvm_x86_default_max_planes(struct kvm *kvm) { return 1; } +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_x86_default_max_planes); + +unsigned kvm_arch_max_planes(struct kvm *kvm) +{ + return kvm_x86_call(max_planes)(kvm); +} struct kvm_plane *x86_alloc_plane(void) {
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 812bd6004a4c..ff57ba568031 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h@@ -800,5 +800,6 @@ static inline bool kvm_is_valid_u_s_cet(struct kvm_vcpu *vcpu, u64 data) struct kvm_plane *x86_alloc_plane(void); void x86_free_plane(struct kvm_plane *plane); +unsigned kvm_x86_default_max_planes(struct kvm *kvm); #endif
--
2.53.0