[PATCH v2 07/45] KVM: x86: Allocate vcpu struct in common x86 code
From: Sean Christopherson <hidden>
Date: 2019-12-18 21:59:31
Also in:
kvm, kvmarm, linux-mips, lkml
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
Move allocation of VMX and SVM vcpus to common x86. Although the struct being allocated is technically a VMX/SVM struct, it can be interpreted directly as a 'struct kvm_vcpu' because of the pre-existing requirement that 'struct kvm_vcpu' be located at offset zero of the arch/vendor vcpu struct. Remove the message from the build-time assertions regarding placement of the struct, as compatibility with the arch usercopy region is no longer the sole dependent on 'struct kvm_vcpu' being at offset zero. Signed-off-by: Sean Christopherson <redacted> --- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/svm.c | 28 +++++++++------------------- arch/x86/kvm/vmx/vmx.c | 24 ++++++++---------------- arch/x86/kvm/x86.c | 16 ++++++++++++---- 4 files changed, 30 insertions(+), 40 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 159a28512e4c..dbc2aa055942 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h@@ -1045,7 +1045,7 @@ struct kvm_x86_ops { void (*vm_destroy)(struct kvm *kvm); /* Create, but do not attach this VCPU */ - struct kvm_vcpu *(*vcpu_create)(struct kvm *kvm, unsigned id); + int (*vcpu_create)(struct kvm *kvm, struct kvm_vcpu *vcpu, unsigned id); void (*vcpu_free)(struct kvm_vcpu *vcpu); void (*vcpu_reset)(struct kvm_vcpu *vcpu, bool init_event);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 1afa10cf365f..4a979278abba 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c@@ -2144,9 +2144,9 @@ static int avic_init_vcpu(struct vcpu_svm *svm) return ret; } -static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id) +static int svm_create_vcpu(struct kvm *kvm, struct kvm_vcpu *vcpu, + unsigned int id) { - struct kvm_vcpu *vcpu; struct vcpu_svm *svm; struct page *page; struct page *msrpm_pages;
@@ -2154,22 +2154,15 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id) struct page *nested_msrpm_pages; int err; - BUILD_BUG_ON_MSG(offsetof(struct vcpu_svm, vcpu) != 0, - "struct kvm_vcpu must be at offset 0 for arch usercopy region"); - - svm = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL_ACCOUNT); - if (!svm) { - err = -ENOMEM; - goto out; - } - vcpu = &svm->vcpu; + BUILD_BUG_ON(offsetof(struct vcpu_svm, vcpu) != 0); + svm = to_svm(vcpu); vcpu->arch.user_fpu = kmem_cache_zalloc(x86_fpu_cache, GFP_KERNEL_ACCOUNT); if (!vcpu->arch.user_fpu) { printk(KERN_ERR "kvm: failed to allocate kvm userspace's fpu\n"); err = -ENOMEM; - goto free_partial_svm; + goto out; } vcpu->arch.guest_fpu = kmem_cache_zalloc(x86_fpu_cache,
@@ -2182,7 +2175,7 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id) err = kvm_vcpu_init(vcpu, kvm, id); if (err) - goto free_svm; + goto free_guest_fpu; err = -ENOMEM; page = alloc_page(GFP_KERNEL_ACCOUNT);
@@ -2226,7 +2219,7 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id) svm_init_osvw(vcpu); - return vcpu; + return 0; free_page4: __free_page(hsave_page);
@@ -2238,14 +2231,12 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id) __free_page(page); uninit: kvm_vcpu_uninit(vcpu); -free_svm: +free_guest_fpu: kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu); free_user_fpu: kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu); -free_partial_svm: - kmem_cache_free(kvm_vcpu_cache, svm); out: - return ERR_PTR(err); + return err; } static void svm_clear_current_vmcb(struct vmcb *vmcb)
@@ -2274,7 +2265,6 @@ static void svm_free_vcpu(struct kvm_vcpu *vcpu) kvm_vcpu_uninit(vcpu); kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu); kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu); - kmem_cache_free(kvm_vcpu_cache, svm); } static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5db455796965..44166309b66c 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c@@ -6675,31 +6675,24 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu) kvm_vcpu_uninit(vcpu); kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu); kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu); - kmem_cache_free(kvm_vcpu_cache, vmx); } -static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) +static int vmx_create_vcpu(struct kvm *kvm, struct kvm_vcpu *vcpu, + unsigned int id) { - struct kvm_vcpu *vcpu; struct vcpu_vmx *vmx; unsigned long *msr_bitmap; int i, cpu, err; - BUILD_BUG_ON_MSG(offsetof(struct vcpu_vmx, vcpu) != 0, - "struct kvm_vcpu must be at offset 0 for arch usercopy region"); - - vmx = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL_ACCOUNT); - if (!vmx) - return ERR_PTR(-ENOMEM); - - vcpu = &vmx->vcpu; + BUILD_BUG_ON(offsetof(struct vcpu_vmx, vcpu) != 0); + vmx = to_vmx(vcpu); vcpu->arch.user_fpu = kmem_cache_zalloc(x86_fpu_cache, GFP_KERNEL_ACCOUNT); if (!vcpu->arch.user_fpu) { printk(KERN_ERR "kvm: failed to allocate kvm userspace's fpu\n"); err = -ENOMEM; - goto free_partial_vcpu; + goto out; } vcpu->arch.guest_fpu = kmem_cache_zalloc(x86_fpu_cache,
@@ -6820,7 +6813,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) vmx->ept_pointer = INVALID_PAGE; - return vcpu; + return 0; free_vmcs: free_loaded_vmcs(vmx->loaded_vmcs);
@@ -6833,9 +6826,8 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) kmem_cache_free(x86_fpu_cache, vcpu->arch.guest_fpu); free_user_fpu: kmem_cache_free(x86_fpu_cache, vcpu->arch.user_fpu); -free_partial_vcpu: - kmem_cache_free(kvm_vcpu_cache, vmx); - return ERR_PTR(err); +out: + return err; } #define L1TF_MSG_SMT "L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.\n"
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 82d41257d2a3..b7f565a43ad7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c@@ -9091,26 +9091,34 @@ static void fx_init(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu) { - void *wbinvd_dirty_mask = vcpu->arch.wbinvd_dirty_mask; - kvmclock_reset(vcpu); kvm_x86_ops->vcpu_free(vcpu); - free_cpumask_var(wbinvd_dirty_mask); + + free_cpumask_var(vcpu->arch.wbinvd_dirty_mask); + kmem_cache_free(kvm_vcpu_cache, vcpu); } struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id) { struct kvm_vcpu *vcpu; + int r; if (kvm_check_tsc_unstable() && atomic_read(&kvm->online_vcpus) != 0) printk_once(KERN_WARNING "kvm: SMP vm created on host with unstable TSC; " "guest TSC will not be reliable\n"); - vcpu = kvm_x86_ops->vcpu_create(kvm, id); + vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL_ACCOUNT); + if (!vcpu) + return ERR_PTR(-ENOMEM); + r = kvm_x86_ops->vcpu_create(kvm, vcpu, id); + if (r) { + kmem_cache_free(kvm_vcpu_cache, vcpu); + return ERR_PTR(r); + } return vcpu; }
--
2.24.1
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