[PATCH v13 03/48] KVM: SVM: Add a proper field for Hyper-V VMCB enlightenments
From: Vitaly Kuznetsov <vkuznets@redhat.com>
Date: 2022-11-01 14:56:32
Also in:
kvm, lkml
Subsystem:
kernel selftest framework, kernel virtual machine (kvm), kernel virtual machine for x86 (kvm/x86), kvm x86 hyper-v (kvm/hyper-v), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Shuah Khan, Paolo Bonzini, Sean Christopherson, Vitaly Kuznetsov, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Sean Christopherson <seanjc@google.com> Add a union to provide hv_enlightenments side-by-side with the sw_reserved bytes that Hyper-V's enlightenments overlay. Casting sw_reserved everywhere is messy, confusing, and unnecessarily unsafe. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> --- arch/x86/include/asm/svm.h | 7 ++++++- arch/x86/kvm/svm/nested.c | 9 ++++----- arch/x86/kvm/svm/svm.h | 5 ++++- arch/x86/kvm/svm/svm_onhyperv.c | 2 +- arch/x86/kvm/svm/svm_onhyperv.h | 15 +++++++-------- tools/testing/selftests/kvm/include/x86_64/svm.h | 5 ++++- .../selftests/kvm/x86_64/hyperv_svm_test.c | 3 +-- 7 files changed, 27 insertions(+), 19 deletions(-)
diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 0361626841bc..6befed2b30a6 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h@@ -5,6 +5,8 @@ #include <uapi/asm/svm.h> #include <uapi/asm/kvm.h> +#include <asm/hyperv-tlfs.h> + /* * 32-bit intercept words in the VMCB Control Area, starting * at Byte offset 000h.
@@ -161,7 +163,10 @@ struct __attribute__ ((__packed__)) vmcb_control_area { * Offset 0x3e0, 32 bytes reserved * for use by hypervisor/software. */ - u8 reserved_sw[32]; + union { + struct hv_enlightenments hv_enlightenments; + u8 reserved_sw[32]; + }; };
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 3131c4476b7b..c8e967f6cafe 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c@@ -179,8 +179,7 @@ void recalc_intercepts(struct vcpu_svm *svm) */ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm) { - struct hv_enlightenments *hve = - (struct hv_enlightenments *)svm->nested.ctl.reserved_sw; + struct hv_enlightenments *hve = &svm->nested.ctl.hv_enlightenments; int i; /*
@@ -369,8 +368,8 @@ void __nested_copy_vmcb_control_to_cache(struct kvm_vcpu *vcpu, /* Hyper-V extensions (Enlightened VMCB) */ if (kvm_hv_hypercall_enabled(vcpu)) { to->clean = from->clean; - memcpy(to->reserved_sw, from->reserved_sw, - sizeof(struct hv_enlightenments)); + memcpy(&to->hv_enlightenments, &from->hv_enlightenments, + sizeof(to->hv_enlightenments)); } }
@@ -1479,7 +1478,7 @@ static void nested_copy_vmcb_cache_to_control(struct vmcb_control_area *dst, dst->virt_ext = from->virt_ext; dst->pause_filter_count = from->pause_filter_count; dst->pause_filter_thresh = from->pause_filter_thresh; - /* 'clean' and 'reserved_sw' are not changed by KVM */ + /* 'clean' and 'hv_enlightenments' are not changed by KVM */ } static int svm_get_nested_state(struct kvm_vcpu *vcpu,
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 6a7686bf6900..9eb2fc76732f 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h@@ -151,7 +151,10 @@ struct vmcb_ctrl_area_cached { u64 nested_cr3; u64 virt_ext; u32 clean; - u8 reserved_sw[32]; + union { + struct hv_enlightenments hv_enlightenments; + u8 reserved_sw[32]; + }; }; struct svm_nested_state {
diff --git a/arch/x86/kvm/svm/svm_onhyperv.c b/arch/x86/kvm/svm/svm_onhyperv.c
index ed5e79392544..422d00fee24a 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.c
+++ b/arch/x86/kvm/svm/svm_onhyperv.c@@ -26,7 +26,7 @@ int svm_hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu) if (!*p_hv_pa_pg) return -ENOMEM; - hve = (struct hv_enlightenments *)to_svm(vcpu)->vmcb->control.reserved_sw; + hve = &to_svm(vcpu)->vmcb->control.hv_enlightenments; hve->partition_assist_page = __pa(*p_hv_pa_pg); hve->hv_vm_id = (unsigned long)vcpu->kvm;
diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h
index 66e61a73caeb..5c664dd7bee2 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.h
+++ b/arch/x86/kvm/svm/svm_onhyperv.h@@ -17,8 +17,10 @@ int svm_hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu); static inline void svm_hv_init_vmcb(struct vmcb *vmcb) { - struct hv_enlightenments *hve = - (struct hv_enlightenments *)vmcb->control.reserved_sw; + struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments; + + BUILD_BUG_ON(sizeof(vmcb->control.hv_enlightenments) != + sizeof(vmcb->control.reserved_sw)); if (npt_enabled && ms_hyperv.nested_features & HV_X64_NESTED_ENLIGHTENED_TLB)
@@ -60,18 +62,15 @@ static inline void svm_hv_vmcb_dirty_nested_enlightenments( struct kvm_vcpu *vcpu) { struct vmcb *vmcb = to_svm(vcpu)->vmcb; - struct hv_enlightenments *hve = - (struct hv_enlightenments *)vmcb->control.reserved_sw; + struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments; if (hve->hv_enlightenments_control.msr_bitmap) vmcb_mark_dirty(vmcb, HV_VMCB_NESTED_ENLIGHTENMENTS); } -static inline void svm_hv_update_vp_id(struct vmcb *vmcb, - struct kvm_vcpu *vcpu) +static inline void svm_hv_update_vp_id(struct vmcb *vmcb, struct kvm_vcpu *vcpu) { - struct hv_enlightenments *hve = - (struct hv_enlightenments *)vmcb->control.reserved_sw; + struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments; u32 vp_index = kvm_hv_get_vpindex(vcpu); if (hve->hv_vp_id != vp_index) {
diff --git a/tools/testing/selftests/kvm/include/x86_64/svm.h b/tools/testing/selftests/kvm/include/x86_64/svm.h
index 89ce2c6b57fe..6e1527aa3419 100644
--- a/tools/testing/selftests/kvm/include/x86_64/svm.h
+++ b/tools/testing/selftests/kvm/include/x86_64/svm.h@@ -123,7 +123,10 @@ struct __attribute__ ((__packed__)) vmcb_control_area { * Offset 0x3e0, 32 bytes reserved * for use by hypervisor/software. */ - u8 reserved_sw[32]; + union { + struct hv_enlightenments hv_enlightenments; + u8 reserved_sw[32]; + }; };
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
index 2fd64b419928..8ef6a4c83cb1 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c@@ -46,8 +46,7 @@ static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm) { unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; struct vmcb *vmcb = svm->vmcb; - struct hv_enlightenments *hve = - (struct hv_enlightenments *)vmcb->control.reserved_sw; + struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments; GUEST_SYNC(1);
--
2.37.3