From c0725420cfdcf6dd9705b164a8c6cba86684080d Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Tue, 25 Nov 2008 20:17:03 +0100 Subject: [PATCH] KVM: SVM: Add helper functions for nested SVM These are helpers for the nested SVM implementation. - nsvm_printk implements a debug printk variant - nested_svm_do calls a handler that can accesses gpa-based memory v3 makes use of the new permission checker v6 changes: - streamline nsvm_debug() - remove printk(KERN_ERR) - SVME check before CPL check - give GP error code - use new EFER constant Acked-by: Joerg Roedel Signed-off-by: Alexander Graf Signed-off-by: Avi Kivity --- arch/x86/kvm/svm.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index e4eb3fd91b90..87debdcd1b90 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -50,6 +50,15 @@ MODULE_LICENSE("GPL"); #define DEBUGCTL_RESERVED_BITS (~(0x3fULL)) +/* Turn on to get debugging output*/ +/* #define NESTED_DEBUG */ + +#ifdef NESTED_DEBUG +#define nsvm_printk(fmt, args...) printk(KERN_INFO fmt, ## args) +#else +#define nsvm_printk(fmt, args...) do {} while(0) +#endif + /* enable NPT for AMD64 and X86 with PAE */ #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE) static bool npt_enabled = true; @@ -1149,6 +1158,82 @@ static int vmmcall_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) return 1; } +static int nested_svm_check_permissions(struct vcpu_svm *svm) +{ + if (!(svm->vcpu.arch.shadow_efer & EFER_SVME) + || !is_paging(&svm->vcpu)) { + kvm_queue_exception(&svm->vcpu, UD_VECTOR); + return 1; + } + + if (svm->vmcb->save.cpl) { + kvm_inject_gp(&svm->vcpu, 0); + return 1; + } + + return 0; +} + +static struct page *nested_svm_get_page(struct vcpu_svm *svm, u64 gpa) +{ + struct page *page; + + down_read(¤t->mm->mmap_sem); + page = gfn_to_page(svm->vcpu.kvm, gpa >> PAGE_SHIFT); + up_read(¤t->mm->mmap_sem); + + if (is_error_page(page)) { + printk(KERN_INFO "%s: could not find page at 0x%llx\n", + __func__, gpa); + kvm_release_page_clean(page); + kvm_inject_gp(&svm->vcpu, 0); + return NULL; + } + return page; +} + +static int nested_svm_do(struct vcpu_svm *svm, + u64 arg1_gpa, u64 arg2_gpa, void *opaque, + int (*handler)(struct vcpu_svm *svm, + void *arg1, + void *arg2, + void *opaque)) +{ + struct page *arg1_page; + struct page *arg2_page = NULL; + void *arg1; + void *arg2 = NULL; + int retval; + + arg1_page = nested_svm_get_page(svm, arg1_gpa); + if(arg1_page == NULL) + return 1; + + if (arg2_gpa) { + arg2_page = nested_svm_get_page(svm, arg2_gpa); + if(arg2_page == NULL) { + kvm_release_page_clean(arg1_page); + return 1; + } + } + + arg1 = kmap_atomic(arg1_page, KM_USER0); + if (arg2_gpa) + arg2 = kmap_atomic(arg2_page, KM_USER1); + + retval = handler(svm, arg1, arg2, opaque); + + kunmap_atomic(arg1, KM_USER0); + if (arg2_gpa) + kunmap_atomic(arg2, KM_USER1); + + kvm_release_page_dirty(arg1_page); + if (arg2_gpa) + kvm_release_page_dirty(arg2_page); + + return retval; +} + static int invalid_op_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) {