[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] x86/monitor: add support for descriptor access events
Adds monitor support for descriptor access events (reads & writes of IDTR/GDTR/LDTR/TR) for the x86 architecture (VMX and SVM). Signed-off-by: Vlad Ioan Topan <itopan@xxxxxxxxxxxxxxx> --- tools/libxc/include/xenctrl.h | 2 ++ tools/libxc/xc_monitor.c | 14 +++++++++++ tools/tests/xen-access/xen-access.c | 29 ++++++++++++++++++++- xen/arch/x86/hvm/hvm.c | 35 ++++++++++++++++++++++++++ xen/arch/x86/hvm/monitor.c | 16 ++++++++++++ xen/arch/x86/hvm/svm/svm.c | 50 +++++++++++++++++++++++++++++++++++++ xen/arch/x86/hvm/vmx/vmx.c | 45 +++++++++++++++++++++++++++++++++ xen/arch/x86/monitor.c | 18 +++++++++++++ xen/arch/x86/vm_event.c | 6 +++++ xen/include/asm-x86/domain.h | 1 + xen/include/asm-x86/hvm/hvm.h | 2 ++ xen/include/asm-x86/hvm/monitor.h | 3 +++ xen/include/asm-x86/hvm/support.h | 2 ++ xen/include/asm-x86/monitor.h | 1 + xen/include/public/domctl.h | 1 + xen/include/public/vm_event.h | 21 ++++++++++++++++ 16 files changed, 245 insertions(+), 1 deletion(-) diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h index a48981a..2de6c61 100644 --- a/tools/libxc/include/xenctrl.h +++ b/tools/libxc/include/xenctrl.h @@ -1984,6 +1984,8 @@ int xc_monitor_mov_to_msr(xc_interface *xch, domid_t domain_id, uint32_t msr, int xc_monitor_singlestep(xc_interface *xch, domid_t domain_id, bool enable); int xc_monitor_software_breakpoint(xc_interface *xch, domid_t domain_id, bool enable); +int xc_monitor_descriptor_access(xc_interface *xch, domid_t domain_id, + bool enable); int xc_monitor_guest_request(xc_interface *xch, domid_t domain_id, bool enable, bool sync); int xc_monitor_debug_exceptions(xc_interface *xch, domid_t domain_id, diff --git a/tools/libxc/xc_monitor.c b/tools/libxc/xc_monitor.c index 15a7c32..f99b6e3 100644 --- a/tools/libxc/xc_monitor.c +++ b/tools/libxc/xc_monitor.c @@ -129,6 +129,20 @@ int xc_monitor_singlestep(xc_interface *xch, domid_t domain_id, return do_domctl(xch, &domctl); } +int xc_monitor_descriptor_access(xc_interface *xch, domid_t domain_id, + bool enable) +{ + DECLARE_DOMCTL; + + domctl.cmd = XEN_DOMCTL_monitor_op; + domctl.domain = domain_id; + domctl.u.monitor_op.op = enable ? XEN_DOMCTL_MONITOR_OP_ENABLE + : XEN_DOMCTL_MONITOR_OP_DISABLE; + domctl.u.monitor_op.event = XEN_DOMCTL_MONITOR_EVENT_DESC_ACCESS; + + return do_domctl(xch, &domctl); +} + int xc_monitor_guest_request(xc_interface *xch, domid_t domain_id, bool enable, bool sync) { diff --git a/tools/tests/xen-access/xen-access.c b/tools/tests/xen-access/xen-access.c index 9d4f957..c567cc0 100644 --- a/tools/tests/xen-access/xen-access.c +++ b/tools/tests/xen-access/xen-access.c @@ -337,7 +337,7 @@ void usage(char* progname) { fprintf(stderr, "Usage: %s [-m] <domain_id> write|exec", progname); #if defined(__i386__) || defined(__x86_64__) - fprintf(stderr, "|breakpoint|altp2m_write|altp2m_exec|debug|cpuid"); + fprintf(stderr, "|breakpoint|altp2m_write|altp2m_exec|debug|cpuid|desc_access"); #elif defined(__arm__) || defined(__aarch64__) fprintf(stderr, "|privcall"); #endif @@ -368,6 +368,7 @@ int main(int argc, char *argv[]) int altp2m = 0; int debug = 0; int cpuid = 0; + int desc_access = 0; uint16_t altp2m_view_id = 0; char* progname = argv[0]; @@ -434,6 +435,10 @@ int main(int argc, char *argv[]) { cpuid = 1; } + else if ( !strcmp(argv[0], "desc_access") ) + { + desc_access = 1; + } #elif defined(__arm__) || defined(__aarch64__) else if ( !strcmp(argv[0], "privcall") ) { @@ -570,6 +575,16 @@ int main(int argc, char *argv[]) goto exit; } } + + if ( desc_access ) + { + rc = xc_monitor_descriptor_access(xch, domain_id, 1); + if ( rc < 0 ) + { + ERROR("Error %d setting descriptor access listener with vm_event\n", rc); + goto exit; + } + } if ( privcall ) { @@ -595,6 +610,8 @@ int main(int argc, char *argv[]) rc = xc_monitor_debug_exceptions(xch, domain_id, 0, 0); if ( cpuid ) rc = xc_monitor_cpuid(xch, domain_id, 0); + if ( desc_access ) + rc = xc_monitor_descriptor_access(xch, domain_id, 0); if ( privcall ) rc = xc_monitor_privileged_call(xch, domain_id, 0); @@ -779,6 +796,16 @@ int main(int argc, char *argv[]) rsp.data = req.data; rsp.data.regs.x86.rip += req.u.cpuid.insn_length; break; + case VM_EVENT_REASON_DESCRIPTOR_ACCESS: + printf("Descriptor access: rip=%016"PRIx64", vcpu %d: "\ + "VMExit info=0x%"PRIx64", descriptor=%d, is write=%d\n", + req.data.regs.x86.rip, + req.vcpu_id, + req.u.desc_access.vmexit.info, + req.u.desc_access.descriptor, + req.u.desc_access.is_write); + rsp.flags |= VM_EVENT_FLAG_EMULATE; + break; default: fprintf(stderr, "UNKNOWN REASON CODE %d\n", req.reason); } diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index ccfae4f..cfe5aa2 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -3645,6 +3645,41 @@ gp_fault: return X86EMUL_EXCEPTION; } +int hvm_descriptor_access_intercept(uint64_t exit_info, uint64_t exit_qualification, + uint8_t descriptor, bool_t is_write) +{ + struct vcpu *v = current; + struct domain *d = v->domain; + struct hvm_emulate_ctxt ctxt = {}; + int rc; + + if ( d->arch.monitor.descriptor_access_enabled ) + { + ASSERT(v->arch.vm_event); + hvm_monitor_descriptor_access(exit_info, exit_qualification, descriptor, is_write); + } + else + { + hvm_emulate_init_once(&ctxt, NULL, guest_cpu_user_regs()); + rc = hvm_emulate_one(&ctxt); + switch ( rc ) + { + case X86EMUL_UNHANDLEABLE: + hvm_inject_hw_exception(TRAP_invalid_op, X86_EVENT_NO_EC); + break; + case X86EMUL_EXCEPTION: + if ( ctxt.ctxt.event_pending ) + hvm_inject_event(&ctxt.ctxt.event); + /* fall through */ + default: + hvm_emulate_writeback(&ctxt); + break; + } + } + + return X86EMUL_OKAY; +} + static bool is_cross_vendor(const struct x86_emulate_state *state, const struct x86_emulate_ctxt *ctxt) { diff --git a/xen/arch/x86/hvm/monitor.c b/xen/arch/x86/hvm/monitor.c index f5cd245..719fd8d 100644 --- a/xen/arch/x86/hvm/monitor.c +++ b/xen/arch/x86/hvm/monitor.c @@ -72,6 +72,22 @@ void hvm_monitor_msr(unsigned int msr, uint64_t value) } } +void hvm_monitor_descriptor_access(uint64_t exit_info, + uint64_t exit_qualification, + uint8_t descriptor, bool_t is_write) +{ + struct vcpu *curr = current; + vm_event_request_t req = { + .reason = VM_EVENT_REASON_DESCRIPTOR_ACCESS, + .u.desc_access.vmexit.info = exit_info, + .u.desc_access.exit_qualification = exit_qualification, + .u.desc_access.descriptor = descriptor, + .u.desc_access.is_write = is_write, + }; + + monitor_traps(curr, 1, &req); +} + static inline unsigned long gfn_of_rip(unsigned long rip) { struct vcpu *curr = current; diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c index 43241d6..63fa253 100644 --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -856,6 +856,23 @@ static void svm_set_rdtsc_exiting(struct vcpu *v, bool_t enable) vmcb_set_general2_intercepts(vmcb, general2_intercepts); } +static void svm_set_descriptor_access_exiting(struct vcpu *v, bool_t enable) +{ + struct vmcb_struct *vmcb = v->arch.hvm_svm.vmcb; + u32 general1_intercepts = vmcb_get_general1_intercepts(vmcb); + u32 mask = GENERAL1_INTERCEPT_IDTR_READ | GENERAL1_INTERCEPT_GDTR_READ \ + | GENERAL1_INTERCEPT_LDTR_READ | GENERAL1_INTERCEPT_TR_READ \ + | GENERAL1_INTERCEPT_IDTR_WRITE | GENERAL1_INTERCEPT_GDTR_WRITE \ + | GENERAL1_INTERCEPT_LDTR_WRITE | GENERAL1_INTERCEPT_TR_WRITE; + + if ( enable ) + general1_intercepts |= mask; + else + general1_intercepts &= ~mask; + + vmcb_set_general1_intercepts(vmcb, general1_intercepts); +} + static unsigned int svm_get_insn_bytes(struct vcpu *v, uint8_t *buf) { struct vmcb_struct *vmcb = v->arch.hvm_svm.vmcb; @@ -2224,6 +2241,7 @@ static struct hvm_function_table __initdata svm_function_table = { .msr_read_intercept = svm_msr_read_intercept, .msr_write_intercept = svm_msr_write_intercept, .set_rdtsc_exiting = svm_set_rdtsc_exiting, + .set_descriptor_access_exiting = svm_set_descriptor_access_exiting, .get_insn_bytes = svm_get_insn_bytes, .nhvm_vcpu_initialise = nsvm_vcpu_initialise, @@ -2642,6 +2660,38 @@ void svm_vmexit_handler(struct cpu_user_regs *regs) case VMEXIT_PAUSE: svm_vmexit_do_pause(regs); break; + + case VMEXIT_IDTR_READ: + hvm_descriptor_access_intercept(vmcb->exitintinfo.bytes, 0, VM_EVENT_DESC_IDTR, 0); + break; + + case VMEXIT_GDTR_READ: + hvm_descriptor_access_intercept(vmcb->exitintinfo.bytes, 0, VM_EVENT_DESC_GDTR, 0); + break; + + case VMEXIT_LDTR_READ: + hvm_descriptor_access_intercept(vmcb->exitintinfo.bytes, 0, VM_EVENT_DESC_LDTR, 0); + break; + + case VMEXIT_TR_READ: + hvm_descriptor_access_intercept(vmcb->exitintinfo.bytes, 0, VM_EVENT_DESC_TR, 0); + break; + + case VMEXIT_IDTR_WRITE: + hvm_descriptor_access_intercept(vmcb->exitintinfo.bytes, 0, VM_EVENT_DESC_IDTR, 1); + break; + + case VMEXIT_GDTR_WRITE: + hvm_descriptor_access_intercept(vmcb->exitintinfo.bytes, 0, VM_EVENT_DESC_GDTR, 1); + break; + + case VMEXIT_LDTR_WRITE: + hvm_descriptor_access_intercept(vmcb->exitintinfo.bytes, 0, VM_EVENT_DESC_LDTR, 1); + break; + + case VMEXIT_TR_WRITE: + hvm_descriptor_access_intercept(vmcb->exitintinfo.bytes, 0, VM_EVENT_DESC_TR, 1); + break; default: unexpected_exit_type: diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index 894d7d4..2b2d193 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -1343,6 +1343,20 @@ static void vmx_set_rdtsc_exiting(struct vcpu *v, bool_t enable) vmx_vmcs_exit(v); } +static void vmx_set_descriptor_access_exiting(struct vcpu *v, bool_t enable) +{ + if ( enable ) + v->arch.hvm_vmx.secondary_exec_control |= + SECONDARY_EXEC_DESCRIPTOR_TABLE_EXITING; + else + v->arch.hvm_vmx.secondary_exec_control &= + ~SECONDARY_EXEC_DESCRIPTOR_TABLE_EXITING; + + vmx_vmcs_enter(v); + vmx_update_secondary_exec_control(v); + vmx_vmcs_exit(v); +} + static void vmx_init_hypercall_page(struct domain *d, void *hypercall_page) { char *p; @@ -2232,6 +2246,7 @@ static struct hvm_function_table __initdata vmx_function_table = { .handle_cd = vmx_handle_cd, .set_info_guest = vmx_set_info_guest, .set_rdtsc_exiting = vmx_set_rdtsc_exiting, + .set_descriptor_access_exiting = vmx_set_descriptor_access_exiting, .nhvm_vcpu_initialise = nvmx_vcpu_initialise, .nhvm_vcpu_destroy = nvmx_vcpu_destroy, .nhvm_vcpu_reset = nvmx_vcpu_reset, @@ -3369,6 +3384,33 @@ static void vmx_handle_xrstors(void) domain_crash(current->domain); } +static void vmx_handle_descriptor_access(uint32_t exit_reason) +{ + uint8_t instr_id; + uint64_t instr_info; + uint64_t exit_qualification; + uint8_t descriptor = VM_EVENT_DESC_INVALID; + + __vmread(EXIT_QUALIFICATION, &exit_qualification); + __vmread(VMX_INSTRUCTION_INFO, &instr_info); + + instr_id = (instr_info >> 28) & 3; /* Instruction identity: bits 29:28 */ + + if ( exit_reason == EXIT_REASON_ACCESS_GDTR_OR_IDTR ) + if ( instr_id & 1 ) + descriptor = VM_EVENT_DESC_IDTR; + else + descriptor = VM_EVENT_DESC_GDTR; + else + if ( instr_id & 1 ) + descriptor = VM_EVENT_DESC_TR; + else + descriptor = VM_EVENT_DESC_LDTR; + + hvm_descriptor_access_intercept(instr_info, exit_qualification, descriptor, + instr_id >= 2); +} + static int vmx_handle_apic_write(void) { unsigned long exit_qualification; @@ -3981,6 +4023,9 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs) case EXIT_REASON_ACCESS_GDTR_OR_IDTR: case EXIT_REASON_ACCESS_LDTR_OR_TR: + vmx_handle_descriptor_access(exit_reason); + break; + case EXIT_REASON_VMX_PREEMPTION_TIMER_EXPIRED: case EXIT_REASON_INVPCID: /* fall through */ diff --git a/xen/arch/x86/monitor.c b/xen/arch/x86/monitor.c index 5f60743..bec63ee 100644 --- a/xen/arch/x86/monitor.c +++ b/xen/arch/x86/monitor.c @@ -211,6 +211,24 @@ int arch_monitor_domctl_event(struct domain *d, break; } + case XEN_DOMCTL_MONITOR_EVENT_DESC_ACCESS: + { + bool_t old_status = ad->monitor.descriptor_access_enabled; + struct vcpu *v; + + if ( unlikely(old_status == requested_status) ) + return -EEXIST; + + domain_pause(d); + ad->monitor.descriptor_access_enabled = requested_status; + + for_each_vcpu ( d, v ) + hvm_funcs.set_descriptor_access_exiting(v, requested_status); + + domain_unpause(d); + break; + } + case XEN_DOMCTL_MONITOR_EVENT_SOFTWARE_BREAKPOINT: { bool_t old_status = ad->monitor.software_breakpoint_enabled; diff --git a/xen/arch/x86/vm_event.c b/xen/arch/x86/vm_event.c index a7ce6ca..502ccc2 100644 --- a/xen/arch/x86/vm_event.c +++ b/xen/arch/x86/vm_event.c @@ -229,6 +229,12 @@ void vm_event_emulate_check(struct vcpu *v, vm_event_response_t *rsp) } break; + case VM_EVENT_REASON_DESCRIPTOR_ACCESS: + if ( rsp->flags & VM_EVENT_FLAG_SET_EMUL_READ_DATA ) + v->arch.vm_event->emul.read = rsp->data.emul.read; + v->arch.vm_event->emulate_flags = rsp->flags; + break; + default: break; }; diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h index ff5267f..b1410a1 100644 --- a/xen/include/asm-x86/domain.h +++ b/xen/include/asm-x86/domain.h @@ -405,6 +405,7 @@ struct arch_domain unsigned int debug_exception_enabled : 1; unsigned int debug_exception_sync : 1; unsigned int cpuid_enabled : 1; + unsigned int descriptor_access_enabled : 1; struct monitor_msr_bitmap *msr_bitmap; } monitor; diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h index eccc25e..ceec7fa 100644 --- a/xen/include/asm-x86/hvm/hvm.h +++ b/xen/include/asm-x86/hvm/hvm.h @@ -174,6 +174,7 @@ struct hvm_function_table { void (*handle_cd)(struct vcpu *v, unsigned long value); void (*set_info_guest)(struct vcpu *v); void (*set_rdtsc_exiting)(struct vcpu *v, bool_t); + void (*set_descriptor_access_exiting)(struct vcpu *v, bool_t); /* Nested HVM */ int (*nhvm_vcpu_initialise)(struct vcpu *v); @@ -444,6 +445,7 @@ int hvm_event_needs_reinjection(uint8_t type, uint8_t vector); uint8_t hvm_combine_hw_exceptions(uint8_t vec1, uint8_t vec2); void hvm_set_rdtsc_exiting(struct domain *d, bool_t enable); +void hvm_set_descriptor_access_exiting(struct domain *d, bool_t enable); static inline int hvm_cpu_up(void) { diff --git a/xen/include/asm-x86/hvm/monitor.h b/xen/include/asm-x86/hvm/monitor.h index 85ca678..35f8b7a 100644 --- a/xen/include/asm-x86/hvm/monitor.h +++ b/xen/include/asm-x86/hvm/monitor.h @@ -38,6 +38,9 @@ bool_t hvm_monitor_cr(unsigned int index, unsigned long value, #define hvm_monitor_crX(cr, new, old) \ hvm_monitor_cr(VM_EVENT_X86_##cr, new, old) void hvm_monitor_msr(unsigned int msr, uint64_t value); +void hvm_monitor_descriptor_access(uint64_t exit_info, + uint64_t exit_qualification, + uint8_t descriptor, bool_t is_write); int hvm_monitor_debug(unsigned long rip, enum hvm_monitor_debug_type type, unsigned long trap_type, unsigned long insn_length); int hvm_monitor_cpuid(unsigned long insn_length, unsigned int leaf, diff --git a/xen/include/asm-x86/hvm/support.h b/xen/include/asm-x86/hvm/support.h index 632eb90..900bfe6 100644 --- a/xen/include/asm-x86/hvm/support.h +++ b/xen/include/asm-x86/hvm/support.h @@ -128,6 +128,8 @@ int hvm_set_efer(uint64_t value); int hvm_set_cr0(unsigned long value, bool_t may_defer); int hvm_set_cr3(unsigned long value, bool_t may_defer); int hvm_set_cr4(unsigned long value, bool_t may_defer); +int hvm_descriptor_access_intercept(uint64_t exit_info, uint64_t exit_qualification, + uint8_t descriptor, bool_t is_write); int hvm_mov_to_cr(unsigned int cr, unsigned int gpr); int hvm_mov_from_cr(unsigned int cr, unsigned int gpr); void hvm_ud_intercept(struct cpu_user_regs *); diff --git a/xen/include/asm-x86/monitor.h b/xen/include/asm-x86/monitor.h index e409373..5eeab3a 100644 --- a/xen/include/asm-x86/monitor.h +++ b/xen/include/asm-x86/monitor.h @@ -77,6 +77,7 @@ static inline uint32_t arch_monitor_get_capabilities(struct domain *d) (1U << XEN_DOMCTL_MONITOR_EVENT_GUEST_REQUEST) | (1U << XEN_DOMCTL_MONITOR_EVENT_DEBUG_EXCEPTION) | (1U << XEN_DOMCTL_MONITOR_EVENT_CPUID) | + (1U << XEN_DOMCTL_MONITOR_EVENT_DESC_ACCESS) | (1U << XEN_DOMCTL_MONITOR_EVENT_INTERRUPT); /* Since we know this is on VMX, we can just call the hvm func */ diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h index 85cbb7c..8ffb38d 100644 --- a/xen/include/public/domctl.h +++ b/xen/include/public/domctl.h @@ -1087,6 +1087,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_domctl_psr_cmt_op_t); #define XEN_DOMCTL_MONITOR_EVENT_CPUID 6 #define XEN_DOMCTL_MONITOR_EVENT_PRIVILEGED_CALL 7 #define XEN_DOMCTL_MONITOR_EVENT_INTERRUPT 8 +#define XEN_DOMCTL_MONITOR_EVENT_DESC_ACCESS 9 struct xen_domctl_monitor_op { uint32_t op; /* XEN_DOMCTL_MONITOR_OP_* */ diff --git a/xen/include/public/vm_event.h b/xen/include/public/vm_event.h index b7487a1..7b18ee4 100644 --- a/xen/include/public/vm_event.h +++ b/xen/include/public/vm_event.h @@ -146,6 +146,8 @@ #define VM_EVENT_REASON_PRIVILEGED_CALL 11 /* An interrupt has been delivered. */ #define VM_EVENT_REASON_INTERRUPT 12 +/* A descriptor table register was accessed. */ +#define VM_EVENT_REASON_DESCRIPTOR_ACCESS 13 /* Supported values for the vm_event_write_ctrlreg index. */ #define VM_EVENT_X86_CR0 0 @@ -259,6 +261,24 @@ struct vm_event_mov_to_msr { uint64_t value; }; +#define VM_EVENT_DESC_INVALID 0 +#define VM_EVENT_DESC_IDTR 1 +#define VM_EVENT_DESC_GDTR 2 +#define VM_EVENT_DESC_LDTR 3 +#define VM_EVENT_DESC_TR 4 + +struct vm_event_desc_access { + union { + uint32_t vmx_instr_info; /* VMX: VMCS Instruction-Information Field */ + uint64_t svm_exitinfo; /* SVM: VMCB EXITINFO Field */ + uint64_t info; + } vmexit; + uint64_t exit_qualification; /* VMX only: VMCS Exit Qualification Field */ + uint8_t descriptor; /* VM_EVENT_DESC_* */ + uint8_t is_write; + uint8_t _pad[6]; +}; + struct vm_event_cpuid { uint32_t insn_length; uint32_t leaf; @@ -313,6 +333,7 @@ typedef struct vm_event_st { struct vm_event_mem_access mem_access; struct vm_event_write_ctrlreg write_ctrlreg; struct vm_event_mov_to_msr mov_to_msr; + struct vm_event_desc_access desc_access; struct vm_event_singlestep singlestep; struct vm_event_debug software_breakpoint; struct vm_event_debug debug_exception; -- 2.7.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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