#include <palacios/vmm_msr.h>
#include <palacios/vmm_mem.h>
#include <palacios/vmm_hypercall.h>
+#include <palacios/vm_guest.h>
#define SYM_PAGE_MSR 0x535
#define SYM_CPUID_NUM 0x90000000
+// A succesfull symcall returns via the RET_HCALL, with the return values in registers
+// A symcall error returns via the ERR_HCALL with the error code in rbx
#define SYM_CALL_RET_HCALL 0x535
+#define SYM_CALL_ERR_HCALL 0x536
+
+
+/* Notes: We use a combination of SYSCALL and SYSENTER Semantics
+ * SYSCALL just sets an EIP, CS/SS seg, and GS seg via swapgs
+ * the RSP is loaded via the structure pointed to by GS
+ * This is safe because it assumes that system calls are guaranteed to be made with an empty kernel stack.
+ * We cannot make that assumption with a symcall, so we have to have our own stack area somewhere.
+ * SYSTENTER does not really use the GS base MSRs, but we do to map to 64 bit kernels
+ */
+
+#define SYMCALL_RIP_MSR 0x536
+#define SYMCALL_RSP_MSR 0x537
+#define SYMCALL_CS_MSR 0x538
+#define SYMCALL_GS_MSR 0x539
+#define SYMCALL_FS_MSR 0x540
static int msr_read(uint_t msr, struct v3_msr * dst, void * priv_data) {
struct guest_info * info = (struct guest_info *)priv_data;
struct v3_sym_state * state = &(info->sym_state);
- dst->value = state->guest_pg_addr;
+ switch (msr) {
+ case SYM_PAGE_MSR:
+ dst->value = state->guest_pg_addr;
+ break;
+ case SYMCALL_RIP_MSR:
+ dst->value = state->sym_call_rip;
+ break;
+ case SYMCALL_RSP_MSR:
+ dst->value = state->sym_call_rsp;
+ break;
+ case SYMCALL_CS_MSR:
+ dst->value = state->sym_call_cs;
+ break;
+ case SYMCALL_GS_MSR:
+ dst->value = state->sym_call_gs;
+ break;
+ case SYMCALL_FS_MSR:
+ dst->value = state->sym_call_fs;
+ break;
+ default:
+ return -1;
+ }
return 0;
}
struct guest_info * info = (struct guest_info *)priv_data;
struct v3_sym_state * state = &(info->sym_state);
+ if (msr == SYM_PAGE_MSR) {
+ PrintDebug("Symbiotic MSR write for page %p\n", (void *)src.value);
- PrintDebug("Symbiotic MSR write for page %p\n", (void *)src.value);
+ if (state->active == 1) {
+ // unmap page
+ struct v3_shadow_region * old_reg = v3_get_shadow_region(info, (addr_t)state->guest_pg_addr);
- if (state->active == 1) {
- // unmap page
- struct v3_shadow_region * old_reg = v3_get_shadow_region(info, (addr_t)state->guest_pg_addr);
+ if (old_reg == NULL) {
+ PrintError("Could not find previously active symbiotic page (%p)\n", (void *)state->guest_pg_addr);
+ return -1;
+ }
- if (old_reg == NULL) {
- PrintError("Could not find previously active symbiotic page (%p)\n", (void *)state->guest_pg_addr);
- return -1;
+ v3_delete_shadow_region(info, old_reg);
}
- v3_delete_shadow_region(info, old_reg);
+ state->guest_pg_addr = src.value;
+ state->guest_pg_addr &= ~0xfffLL;
+
+ state->active = 1;
+
+ // map page
+ v3_add_shadow_mem(info, (addr_t)state->guest_pg_addr,
+ (addr_t)(state->guest_pg_addr + PAGE_SIZE_4KB - 1),
+ state->sym_page_pa);
+
+
+ } else if (msr == SYMCALL_RIP_MSR) {
+ state->sym_call_rip = src.value;
+ } else if (msr == SYMCALL_RSP_MSR) {
+ state->sym_call_rsp = src.value;
+ } else if (msr == SYMCALL_CS_MSR) {
+ state->sym_call_cs = src.value;
+ } else if (msr == SYMCALL_GS_MSR) {
+ state->sym_call_gs = src.value;
+ } else if (msr == SYMCALL_FS_MSR) {
+ state->sym_call_fs = src.value;
+ } else {
+ PrintError("Invalid Symbiotic MSR write (0x%x)\n", msr);
+ return -1;
}
- state->guest_pg_addr = src.value;
- state->guest_pg_addr &= ~0xfffLL;
-
- state->active = 1;
-
- // map page
- v3_add_shadow_mem(info, (addr_t)state->guest_pg_addr,
- (addr_t)(state->guest_pg_addr + PAGE_SIZE_4KB - 1),
- state->sym_page_pa);
-
return 0;
}
uint32_t * eax, uint32_t * ebx,
uint32_t * ecx, uint32_t * edx,
void * private_data) {
+ extern v3_cpu_arch_t v3_cpu_types[];
+
+ *eax = *(uint32_t *)"V3V";
+
+ if ((v3_cpu_types[info->cpu_id] == V3_SVM_CPU) ||
+ (v3_cpu_types[info->cpu_id] == V3_SVM_REV3_CPU)) {
+ *ebx = *(uint32_t *)"SVM";
+ } else if ((v3_cpu_types[info->cpu_id] == V3_VMX_CPU) ||
+ (v3_cpu_types[info->cpu_id] == V3_VMX_EPT_CPU)) {
+ *ebx = *(uint32_t *)"VMX";
+ }
- memset(eax, 0, sizeof(uint32_t));
- memcpy(eax, "V3V", 3);
return 0;
}
static int sym_call_ret(struct guest_info * info, uint_t hcall_id, void * private_data);
+static int sym_call_err(struct guest_info * info, uint_t hcall_id, void * private_data);
v3_hook_cpuid(info, SYM_CPUID_NUM, cpuid_fn, info);
+ v3_hook_msr(info, SYMCALL_RIP_MSR, msr_read, msr_write, info);
+ v3_hook_msr(info, SYMCALL_RSP_MSR, msr_read, msr_write, info);
+ v3_hook_msr(info, SYMCALL_CS_MSR, msr_read, msr_write, info);
+ v3_hook_msr(info, SYMCALL_GS_MSR, msr_read, msr_write, info);
+ v3_hook_msr(info, SYMCALL_FS_MSR, msr_read, msr_write, info);
v3_register_hypercall(info, SYM_CALL_RET_HCALL, sym_call_ret, NULL);
+ v3_register_hypercall(info, SYM_CALL_ERR_HCALL, sym_call_err, NULL);
return 0;
}
}
-
-static int sym_call_ret(struct guest_info * info, uint_t hcall_id, void * private_data) {
+static int sym_call_err(struct guest_info * info, uint_t hcall_id, void * private_data) {
struct v3_sym_state * state = (struct v3_sym_state *)&(info->sym_state);
- struct v3_sym_context * old_ctx = (struct v3_sym_context *)&(state->old_ctx);
+ PrintError("sym call error\n");
- PrintError("Return from sym call\n");
+ state->sym_call_errno = (int)info->vm_regs.rbx;
v3_print_guest_state(info);
v3_print_mem_map(info);
-
- if (state->notifier != NULL) {
- if (state->notifier(info, state->private_data) == -1) {
- PrintError("Error in return from symcall.\n");
- return -1;
- }
- }
-
-
- // restore guest state
- memcpy(&(info->vm_regs), &(old_ctx->vm_regs), sizeof(struct v3_gprs));
- memcpy(&(info->segments.cs), &(old_ctx->cs), sizeof(struct v3_segment));
- memcpy(&(info->segments.ss), &(old_ctx->ss), sizeof(struct v3_segment));
- info->segments.gs.base = old_ctx->gs_base;
- info->segments.fs.base = old_ctx->fs_base;
- info->rip = old_ctx->rip;
- info->cpl = old_ctx->cpl;
-
-
- PrintDebug("restoring guest state\n");
- v3_print_guest_state(info);
-
// clear sym flags
- state->call_active = 0;
-
+ state->sym_call_error = 1;
+ state->sym_call_returned = 1;
- return 0;
+ return -1;
}
-
-int v3_sym_call(struct guest_info * info,
- uint64_t arg0, uint64_t arg1,
- uint64_t arg2, uint64_t arg3,
- uint64_t arg4, uint64_t arg5,
- int (*notifier)(struct guest_info * info, void * private_data),
- void * private_data) {
+static int sym_call_ret(struct guest_info * info, uint_t hcall_id, void * private_data) {
struct v3_sym_state * state = (struct v3_sym_state *)&(info->sym_state);
+ // PrintError("Return from sym call (ID=%x)\n", hcall_id);
+ // v3_print_guest_state(info);
- PrintDebug("Making Sym call\n");
-
- if ((state->sym_page->sym_call_enabled == 0) ||
- (state->call_active == 1) ||
- (state->call_pending == 1)) {
- return -1;
- }
+ state->sym_call_returned = 1;
- state->args[0] = arg0;
- state->args[1] = arg1;
- state->args[2] = arg2;
- state->args[3] = arg3;
- state->args[4] = arg4;
- state->args[5] = arg5;
+ return 0;
+}
- state->notifier = notifier;
- state->private_data = private_data;
+static int execute_symcall(struct guest_info * info) {
- state->call_pending = 1;
+ while (info->sym_state.sym_call_returned == 0) {
+ if (v3_vm_enter(info) == -1) {
+ PrintError("Error in Sym call\n");
+ return -1;
+ }
+ }
return 0;
}
-
-int v3_activate_sym_call(struct guest_info * info) {
+int v3_sym_call(struct guest_info * info,
+ uint64_t call_num, sym_arg_t * arg0,
+ sym_arg_t * arg1, sym_arg_t * arg2,
+ sym_arg_t * arg3, sym_arg_t * arg4) {
struct v3_sym_state * state = (struct v3_sym_state *)&(info->sym_state);
struct v3_sym_context * old_ctx = (struct v3_sym_context *)&(state->old_ctx);
struct v3_segment sym_cs;
struct v3_segment sym_ss;
+ uint64_t trash_args[5] = { [0 ... 4] = 0 };
+ // PrintDebug("Making Sym call\n");
+ // v3_print_guest_state(info);
- if ((state->sym_page->sym_call_enabled == 0) ||
- (state->call_pending == 0)) {
- // Unable to make sym call or none pending
- if (state->call_active == 1) {
- PrintError("handled exit while in symcall\n");
- }
- return 0;
+ if ((state->sym_page->sym_call_enabled == 0) ||
+ (state->sym_call_active == 1)) {
+ return -1;
}
-
-
- PrintDebug("Activating Symbiotic call\n");
- v3_print_guest_state(info);
-
+
+ if (!arg0) arg0 = &trash_args[0];
+ if (!arg1) arg1 = &trash_args[1];
+ if (!arg2) arg2 = &trash_args[2];
+ if (!arg3) arg3 = &trash_args[3];
+ if (!arg4) arg4 = &trash_args[4];
// Save the old context
memcpy(&(old_ctx->vm_regs), &(info->vm_regs), sizeof(struct v3_gprs));
old_ctx->fs_base = info->segments.fs.base;
old_ctx->rip = info->rip;
old_ctx->cpl = info->cpl;
+ old_ctx->flags = info->ctrl_regs.rflags;
-
-
// Setup the sym call context
- info->rip = state->sym_page->sym_call_rip;
- info->vm_regs.rsp = state->sym_page->sym_call_rsp;
+ info->rip = state->sym_call_rip;
+ info->vm_regs.rsp = state->sym_call_rsp; // old contest rsp is saved in vm_regs
- v3_translate_segment(info, state->sym_page->sym_call_cs, &sym_cs);
+ v3_translate_segment(info, state->sym_call_cs, &sym_cs);
memcpy(&(info->segments.cs), &sym_cs, sizeof(struct v3_segment));
- v3_translate_segment(info, state->sym_page->sym_call_cs + 8, &sym_ss);
+ v3_translate_segment(info, state->sym_call_cs + 8, &sym_ss);
memcpy(&(info->segments.ss), &sym_ss, sizeof(struct v3_segment));
- info->segments.gs.base = state->sym_page->sym_call_gs;
- info->segments.fs.base = 0;
+ info->segments.gs.base = state->sym_call_gs;
+ info->segments.fs.base = state->sym_call_fs;
info->cpl = 0;
- info->vm_regs.rax = state->args[0];
- info->vm_regs.rbx = state->args[1];
- info->vm_regs.rcx = state->args[2];
- info->vm_regs.rdx = state->args[3];
- info->vm_regs.rsi = state->args[4];
- info->vm_regs.rdi = state->args[5];
+ info->vm_regs.rax = call_num;
+ info->vm_regs.rbx = *arg0;
+ info->vm_regs.rcx = *arg1;
+ info->vm_regs.rdx = *arg2;
+ info->vm_regs.rsi = *arg3;
+ info->vm_regs.rdi = *arg4;
// Mark sym call as active
- state->call_pending = 0;
- state->call_active = 1;
+ state->sym_call_active = 1;
+ state->sym_call_returned = 0;
+ // PrintDebug("Sym state\n");
+ // v3_print_guest_state(info);
+
+ // Do the sym call entry
+ if (execute_symcall(info) == -1) {
+ PrintError("SYMCALL error\n");
+ return -1;
+ }
+
+ // clear sym flags
+ state->sym_call_active = 0;
+
+ *arg0 = info->vm_regs.rbx;
+ *arg1 = info->vm_regs.rcx;
+ *arg2 = info->vm_regs.rdx;
+ *arg3 = info->vm_regs.rsi;
+ *arg4 = info->vm_regs.rdi;
+
+ // restore guest state
+ memcpy(&(info->vm_regs), &(old_ctx->vm_regs), sizeof(struct v3_gprs));
+ memcpy(&(info->segments.cs), &(old_ctx->cs), sizeof(struct v3_segment));
+ memcpy(&(info->segments.ss), &(old_ctx->ss), sizeof(struct v3_segment));
+ info->segments.gs.base = old_ctx->gs_base;
+ info->segments.fs.base = old_ctx->fs_base;
+ info->rip = old_ctx->rip;
+ info->cpl = old_ctx->cpl;
+ info->ctrl_regs.rflags = old_ctx->flags;
- PrintDebug("Sym state\n");
- v3_print_guest_state(info);
- return 1;
+
+ // PrintError("restoring guest state\n");
+ // v3_print_guest_state(info);
+
+ return 0;
}
+
+
