fixed crash issue due to inproperly saving host state

diff --git a/palacios/src/palacios/svm.c b/palacios/src/palacios/svm.c
index 9434e49..76a57dd 100644 (file)
--- a/palacios/src/palacios/svm.c
+++ b/palacios/src/palacios/svm.c
@@ -45,10 +45,14 @@
 #include <palacios/svm_io.h>
 
 
+
+// This is a global pointer to the host's VMCB
+static void * host_vmcb = NULL;
+
 extern void v3_stgi();
 extern void v3_clgi();
 //extern int v3_svm_launch(vmcb_t * vmcb, struct v3_gprs * vm_regs, uint64_t * fs, uint64_t * gs);
-extern int v3_svm_launch(vmcb_t * vmcb, struct v3_gprs * vm_regs);
+extern int v3_svm_launch(vmcb_t * vmcb, struct v3_gprs * vm_regs, vmcb_t * host_vmcb);
 
 
 static vmcb_t * Allocate_VMCB() {
@@ -281,86 +285,32 @@ static int start_svm_guest(struct guest_info *info) {
        ullong_t tmp_tsc;
        
 
-#ifdef __V3_64BIT__
-
-#define MSR_LSTAR         0xc0000082
-#define MSR_CSTAR         0xc0000083
-#define MSR_SF_MASK       0xc0000084
-#define MSR_GS_BASE       0xc0000101
-#define MSR_KERNGS_BASE   0xc0000102
-       struct v3_msr host_cstar;
-       struct v3_msr host_lstar;
-       struct v3_msr host_syscall_mask;
-       struct v3_msr host_gs_base;
-       struct v3_msr host_kerngs_base;
-
-#else 
-
-#define MSR_SYSENTER_CS       0x00000174
-#define MSR_SYSENTER_ESP      0x00000175
-#define MSR_SYSENTER_EIP      0x00000176
-
-       struct v3_msr host_sysenter_cs;
-       struct v3_msr host_sysenter_esp;
-       struct v3_msr host_sysenter_eip;
-
-#endif
-
-#define MSR_STAR              0xc0000081
-       struct v3_msr host_star;
-
-
        /*
          PrintDebug("SVM Entry to CS=%p  rip=%p...\n", 
          (void *)(addr_t)info->segments.cs.base, 
          (void *)(addr_t)info->rip);
        */
 
+       // disable global interrupts for vm state transition
+       v3_clgi();
+
 
-#ifdef __V3_64BIT__
-       v3_get_msr(MSR_SF_MASK, &(host_syscall_mask.hi), &(host_syscall_mask.lo));
-       v3_get_msr(MSR_LSTAR, &(host_lstar.hi), &(host_lstar.lo));
-       v3_get_msr(MSR_CSTAR, &(host_cstar.hi), &(host_cstar.lo));
-       v3_get_msr(MSR_GS_BASE, &(host_gs_base.hi), &(host_gs_base.lo));
-       v3_get_msr(MSR_KERNGS_BASE, &(host_kerngs_base.hi), &(host_kerngs_base.lo));
-#else 
-       v3_get_msr(MSR_SYSENTER_CS, &(host_sysenter_cs.hi), &(host_sysenter_cs.lo));
-       v3_get_msr(MSR_SYSENTER_ESP, &(host_sysenter_esp.hi), &(host_sysenter_esp.lo));
-       v3_get_msr(MSR_SYSENTER_EIP, &(host_sysenter_eip.hi), &(host_sysenter_eip.lo));
-#endif
-       v3_get_msr(MSR_STAR, &(host_star.hi), &(host_star.lo));
 
        rdtscll(info->time_state.cached_host_tsc);
        //    guest_ctrl->TSC_OFFSET = info->time_state.guest_tsc - info->time_state.cached_host_tsc;
        
-       v3_svm_launch((vmcb_t*)V3_PAddr(info->vmm_data), &(info->vm_regs));
+       v3_svm_launch((vmcb_t*)V3_PAddr(info->vmm_data), &(info->vm_regs), (vmcb_t *)host_vmcb);
        
        rdtscll(tmp_tsc);
-       
-#ifdef __V3_64BIT__
-       v3_set_msr(MSR_SF_MASK, host_syscall_mask.hi, host_syscall_mask.lo);
-       v3_set_msr(MSR_LSTAR, host_lstar.hi, host_lstar.lo);
-       v3_set_msr(MSR_CSTAR, host_cstar.hi, host_cstar.lo);
-       v3_set_msr(MSR_GS_BASE, host_gs_base.hi, host_gs_base.lo);
-       v3_set_msr(MSR_KERNGS_BASE, host_kerngs_base.hi, host_kerngs_base.lo);
-#else 
-       v3_set_msr(MSR_SYSENTER_CS, host_sysenter_cs.hi, host_sysenter_cs.lo);
-       v3_set_msr(MSR_SYSENTER_ESP, host_sysenter_esp.hi, host_sysenter_esp.lo);
-       v3_set_msr(MSR_SYSENTER_EIP, host_sysenter_eip.hi, host_sysenter_eip.lo);
-#endif
-       v3_set_msr(MSR_STAR, host_star.hi, host_star.lo);
 
        
        //PrintDebug("SVM Returned\n");
 
-
+       // reenable global interrupts after vm exit
+       v3_stgi();
 
        v3_update_time(info, tmp_tsc - info->time_state.cached_host_tsc);
        num_exits++;
-
-       //PrintDebug("Turning on global interrupts\n");
-       v3_stgi();
-       v3_clgi();
        
        if ((num_exits % 5000) == 0) {
            PrintDebug("SVM Exit number %d\n", num_exits);
@@ -370,7 +320,6 @@ static int start_svm_guest(struct guest_info *info) {
            }
        }
 
-
      
        if (v3_handle_svm_exit(info) != 0) {
            vmcb_ctrl_t * guest_ctrl = GET_VMCB_CTRL_AREA((vmcb_t*)(info->vmm_data));
@@ -487,7 +436,6 @@ static int has_svm_nested_paging() {
 
 void v3_init_SVM(struct v3_ctrl_ops * vmm_ops) {
     reg_ex_t msr;
-    void * host_state;
     extern v3_cpu_arch_t v3_cpu_type;
 
     // Enable SVM on the CPU
@@ -499,15 +447,15 @@ void v3_init_SVM(struct v3_ctrl_ops * vmm_ops) {
 
 
     // Setup the host state save area
-    host_state = V3_AllocPages(4);
+    host_vmcb = V3_AllocPages(4);
 
 
     /* 64-BIT-ISSUE */
     //  msr.e_reg.high = 0;
-    //msr.e_reg.low = (uint_t)host_state;
-    msr.r_reg = (addr_t)host_state;
+    //msr.e_reg.low = (uint_t)host_vmcb;
+    msr.r_reg = (addr_t)host_vmcb;
 
-    PrintDebug("Host State being saved at %p\n", (void *)(addr_t)host_state);
+    PrintDebug("Host State being saved at %p\n", (void *)(addr_t)host_vmcb);
     v3_set_msr(SVM_VM_HSAVE_PA_MSR, msr.e_reg.high, msr.e_reg.low);
 
     if (has_svm_nested_paging() == 1) {

diff --git a/palacios/src/palacios/svm_lowlevel.S b/palacios/src/palacios/svm_lowlevel.S
index 975fe98..ac11b36 100644 (file)
--- a/palacios/src/palacios/svm_lowlevel.S
+++ b/palacios/src/palacios/svm_lowlevel.S
@@ -18,6 +18,9 @@
 #define clgi   .byte 0x0F,0x01,0xDD
 
 
+#define SVM_VM_HSAVE_PA_MSR .dword 0xc0010117
+
+
 #ifdef __V3_32BIT__
 
 #define Save_SVM_Registers(location)   \
@@ -49,14 +52,17 @@
        popl    %eax;
 
 
+// 32 bit GCC passes arguments via stack
+
 v3_svm_launch:
        push    %ebp;
        movl    %esp, %ebp;
        pushf;
-       push    %fs;
-       push    %gs;
        pusha;
 
+       movl    16(%ebp), %eax;
+       vmsave;
+
        pushl   12(%ebp);
        pushl   8(%ebp);
 
@@ -71,9 +77,11 @@ v3_svm_launch:
 
        addl    $4, %esp;
 
+
+       movl    16(%ebp), %eax;
+       vmload;
+
        popa;
-       pop     %gs;
-       pop     %fs;
        popf;
        pop     %ebp;
        ret
@@ -156,29 +164,19 @@ v3_svm_launch:
        popq %rbx;                      \
        popq %rbp;                      
 
+
+// Note that this is only for 64 bit GCC, 32 bit GCC passes via stack
 // VMCB => RDI
 // vm_regs => RSI
-// ptr to fs => RDX
-// ptr to gs => RCX
+// HOST VMCB => RDX
 
 v3_svm_launch:
        pushf;
-       push    %fs;
-       push    %gs;
        PUSHA
-
-
-
-//     pushq   %rdx // fs
-//     pushq   %rcx // gs
-
-
-//     pushq   (%rdx)
-//     pop     %fs
-//     pushq   (%rcx)
-//     pop     %gs
-
-
+       
+       pushq   %rdx;
+       movq    %rdx, %rax;
+       vmsave;
 
        pushq   %rsi
 
@@ -195,21 +193,11 @@ v3_svm_launch:
 
        addq $8, %rsp
 
-//     popq    %rcx
-//     popq    %rdx
-
-//     push    %fs
-//     popq    %rax
-//     movq    %rax, (%rdx)
-
-//     push    %gs
-//     popq    %rax
-//     movq    %rax, (%rcx)
 
+       popq %rax;
+       vmload;
 
        POPA
-       pop     %gs;
-       pop     %fs;
        popf;
        ret