From: Izik Eidus Date: Mon, 1 Oct 2007 20:14:18 +0000 (+0200) Subject: KVM: Add general accessors to read and write guest memory X-Git-Tag: v2.6.25-rc1~1138^2~228 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=195aefde9cc2cee38dd54ef92a866721fba4413e;p=linux-2.6 KVM: Add general accessors to read and write guest memory Signed-off-by: Izik Eidus Signed-off-by: Avi Kivity --- diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h index 80cfb99fff..1965438f18 100644 --- a/drivers/kvm/kvm.h +++ b/drivers/kvm/kvm.h @@ -559,6 +559,15 @@ extern hpa_t bad_page_address; gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn); struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn); +int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, + int len); +int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len); +int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data, + int offset, int len); +int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data, + unsigned long len); +int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len); +int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len); struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn); void mark_page_dirty(struct kvm *kvm, gfn_t gfn); diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 9510e2276c..cac328b842 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -400,22 +400,16 @@ static int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3) gfn_t pdpt_gfn = cr3 >> PAGE_SHIFT; unsigned offset = ((cr3 & (PAGE_SIZE-1)) >> 5) << 2; int i; - u64 *pdpt; int ret; - struct page *page; u64 pdpte[ARRAY_SIZE(vcpu->pdptrs)]; mutex_lock(&vcpu->kvm->lock); - page = gfn_to_page(vcpu->kvm, pdpt_gfn); - if (!page) { + ret = kvm_read_guest_page(vcpu->kvm, pdpt_gfn, pdpte, + offset * sizeof(u64), sizeof(pdpte)); + if (ret < 0) { ret = 0; goto out; } - - pdpt = kmap_atomic(page, KM_USER0); - memcpy(pdpte, pdpt+offset, sizeof(pdpte)); - kunmap_atomic(pdpt, KM_USER0); - for (i = 0; i < ARRAY_SIZE(pdpte); ++i) { if ((pdpte[i] & 1) && (pdpte[i] & 0xfffffff0000001e6ull)) { ret = 0; @@ -962,6 +956,127 @@ struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) } EXPORT_SYMBOL_GPL(gfn_to_page); +static int next_segment(unsigned long len, int offset) +{ + if (len > PAGE_SIZE - offset) + return PAGE_SIZE - offset; + else + return len; +} + +int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, + int len) +{ + void *page_virt; + struct page *page; + + page = gfn_to_page(kvm, gfn); + if (!page) + return -EFAULT; + page_virt = kmap_atomic(page, KM_USER0); + + memcpy(data, page_virt + offset, len); + + kunmap_atomic(page_virt, KM_USER0); + return 0; +} +EXPORT_SYMBOL_GPL(kvm_read_guest_page); + +int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len) +{ + gfn_t gfn = gpa >> PAGE_SHIFT; + int seg; + int offset = offset_in_page(gpa); + int ret; + + while ((seg = next_segment(len, offset)) != 0) { + ret = kvm_read_guest_page(kvm, gfn, data, offset, seg); + if (ret < 0) + return ret; + offset = 0; + len -= seg; + data += seg; + ++gfn; + } + return 0; +} +EXPORT_SYMBOL_GPL(kvm_read_guest); + +int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data, + int offset, int len) +{ + void *page_virt; + struct page *page; + + page = gfn_to_page(kvm, gfn); + if (!page) + return -EFAULT; + page_virt = kmap_atomic(page, KM_USER0); + + memcpy(page_virt + offset, data, len); + + kunmap_atomic(page_virt, KM_USER0); + mark_page_dirty(kvm, gfn); + return 0; +} +EXPORT_SYMBOL_GPL(kvm_write_guest_page); + +int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data, + unsigned long len) +{ + gfn_t gfn = gpa >> PAGE_SHIFT; + int seg; + int offset = offset_in_page(gpa); + int ret; + + while ((seg = next_segment(len, offset)) != 0) { + ret = kvm_write_guest_page(kvm, gfn, data, offset, seg); + if (ret < 0) + return ret; + offset = 0; + len -= seg; + data += seg; + ++gfn; + } + return 0; +} + +int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len) +{ + void *page_virt; + struct page *page; + + page = gfn_to_page(kvm, gfn); + if (!page) + return -EFAULT; + page_virt = kmap_atomic(page, KM_USER0); + + memset(page_virt + offset, 0, len); + + kunmap_atomic(page_virt, KM_USER0); + return 0; +} +EXPORT_SYMBOL_GPL(kvm_clear_guest_page); + +int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len) +{ + gfn_t gfn = gpa >> PAGE_SHIFT; + int seg; + int offset = offset_in_page(gpa); + int ret; + + while ((seg = next_segment(len, offset)) != 0) { + ret = kvm_clear_guest_page(kvm, gfn, offset, seg); + if (ret < 0) + return ret; + offset = 0; + len -= seg; + ++gfn; + } + return 0; +} +EXPORT_SYMBOL_GPL(kvm_clear_guest); + /* WARNING: Does not work on aliased pages. */ void mark_page_dirty(struct kvm *kvm, gfn_t gfn) { @@ -988,21 +1103,13 @@ int emulator_read_std(unsigned long addr, gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr); unsigned offset = addr & (PAGE_SIZE-1); unsigned tocopy = min(bytes, (unsigned)PAGE_SIZE - offset); - unsigned long pfn; - struct page *page; - void *page_virt; + int ret; if (gpa == UNMAPPED_GVA) return X86EMUL_PROPAGATE_FAULT; - pfn = gpa >> PAGE_SHIFT; - page = gfn_to_page(vcpu->kvm, pfn); - if (!page) + ret = kvm_read_guest(vcpu->kvm, gpa, data, tocopy); + if (ret < 0) return X86EMUL_UNHANDLEABLE; - page_virt = kmap_atomic(page, KM_USER0); - - memcpy(data, page_virt + offset, tocopy); - - kunmap_atomic(page_virt, KM_USER0); bytes -= tocopy; data += tocopy; @@ -1095,19 +1202,12 @@ static int emulator_read_emulated(unsigned long addr, static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, const void *val, int bytes) { - struct page *page; - void *virt; + int ret; - if (((gpa + bytes - 1) >> PAGE_SHIFT) != (gpa >> PAGE_SHIFT)) - return 0; - page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT); - if (!page) + ret = kvm_write_guest(vcpu->kvm, gpa, val, bytes); + if (ret < 0) return 0; - mark_page_dirty(vcpu->kvm, gpa >> PAGE_SHIFT); - virt = kmap_atomic(page, KM_USER0); kvm_mmu_pte_write(vcpu, gpa, val, bytes); - memcpy(virt + offset_in_page(gpa), val, bytes); - kunmap_atomic(virt, KM_USER0); return 1; } diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c index 439873a25c..894fd45ecc 100644 --- a/drivers/kvm/vmx.c +++ b/drivers/kvm/vmx.c @@ -1387,33 +1387,28 @@ static void vmx_set_gdt(struct kvm_vcpu *vcpu, struct descriptor_table *dt) static int init_rmode_tss(struct kvm* kvm) { - struct page *p1, *p2, *p3; gfn_t fn = rmode_tss_base(kvm) >> PAGE_SHIFT; - char *page; - - p1 = gfn_to_page(kvm, fn++); - p2 = gfn_to_page(kvm, fn++); - p3 = gfn_to_page(kvm, fn); + u16 data = 0; + int r; - if (!p1 || !p2 || !p3) { - kvm_printf(kvm,"%s: gfn_to_page failed\n", __FUNCTION__); + r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE); + if (r < 0) + return 0; + data = TSS_BASE_SIZE + TSS_REDIRECTION_SIZE; + r = kvm_write_guest_page(kvm, fn++, &data, 0x66, sizeof(u16)); + if (r < 0) + return 0; + r = kvm_clear_guest_page(kvm, fn++, 0, PAGE_SIZE); + if (r < 0) + return 0; + r = kvm_clear_guest_page(kvm, fn, 0, PAGE_SIZE); + if (r < 0) + return 0; + data = ~0; + r = kvm_write_guest_page(kvm, fn, &data, RMODE_TSS_SIZE - 2 * PAGE_SIZE - 1, + sizeof(u8)); + if (r < 0) return 0; - } - - page = kmap_atomic(p1, KM_USER0); - clear_page(page); - *(u16*)(page + 0x66) = TSS_BASE_SIZE + TSS_REDIRECTION_SIZE; - kunmap_atomic(page, KM_USER0); - - page = kmap_atomic(p2, KM_USER0); - clear_page(page); - kunmap_atomic(page, KM_USER0); - - page = kmap_atomic(p3, KM_USER0); - clear_page(page); - *(page + RMODE_TSS_SIZE - 2 * PAGE_SIZE - 1) = ~0; - kunmap_atomic(page, KM_USER0); - return 1; }