X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=blobdiff_plain;f=palacios%2Fsrc%2Fpalacios%2Fvmm_sym_iface.c;h=83959555e33fee6587f3152666e889e777c1dc9f;hp=5cb4e353505c6b86c9b020f9b972e13bd0ff7c71;hb=cfcc5717f659b3ed2954f41cf363d3bceae8dc84;hpb=ed8feff1d5dd6bf028cd5ba0960ec125505d7597

diff --git a/palacios/src/palacios/vmm_sym_iface.c b/palacios/src/palacios/vmm_sym_iface.c
index 5cb4e35..8395955 100644
--- a/palacios/src/palacios/vmm_sym_iface.c
+++ b/palacios/src/palacios/vmm_sym_iface.c
@@ -22,19 +22,59 @@
 #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;
 }
@@ -43,31 +83,47 @@ static int msr_write(uint_t msr, struct v3_msr src, void * priv_data) {
     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;
 }
 
@@ -75,15 +131,25 @@ static int cpuid_fn(struct guest_info * info, uint32_t cpuid,
 		    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);
 
 
 
@@ -102,8 +168,14 @@ int v3_init_sym_iface(struct guest_info * info) {
 
     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;
 }
@@ -147,100 +219,69 @@ int v3_sym_unmap_pci_passthrough(struct guest_info * info, uint_t bus, uint_t de
 }
 
 
-
-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));
@@ -250,37 +291,67 @@ int v3_activate_sym_call(struct guest_info * info) {
     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;
 }
+
+