Boot with virtual == physical to get closer to native Linux.

[mirror_ubuntu-artful-kernel.git] / drivers / lguest / interrupts_and_traps.c

diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c
index a57d757eab6e16caae0b4cccbe152a43b00f1245..3271c0031a1bb667a0c6c5729920e93aa47078f1 100644 (file)
--- a/drivers/lguest/interrupts_and_traps.c
+++ b/drivers/lguest/interrupts_and_traps.c
@@ -62,8 +62,9 @@ static void push_guest_stack(struct lguest *lg, unsigned long *gstack, u32 val)
  * it). */
 static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err)
 {
-       unsigned long gstack;
+       unsigned long gstack, origstack;
        u32 eflags, ss, irq_enable;
+       unsigned long virtstack;
 
        /* There are two cases for interrupts: one where the Guest is already
         * in the kernel, and a more complex one where the Guest is in
@@ -71,8 +72,10 @@ static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err)
        if ((lg->regs->ss&0x3) != GUEST_PL) {
                /* The Guest told us their kernel stack with the SET_STACK
                 * hypercall: both the virtual address and the segment */
-               gstack = guest_pa(lg, lg->esp1);
+               virtstack = lg->esp1;
                ss = lg->ss1;
+
+               origstack = gstack = guest_pa(lg, virtstack);
                /* We push the old stack segment and pointer onto the new
                 * stack: when the Guest does an "iret" back from the interrupt
                 * handler the CPU will notice they're dropping privilege
@@ -81,8 +84,10 @@ static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err)
                push_guest_stack(lg, &gstack, lg->regs->esp);
        } else {
                /* We're staying on the same Guest (kernel) stack. */
-               gstack = guest_pa(lg, lg->regs->esp);
+               virtstack = lg->regs->esp;
                ss = lg->regs->ss;
+
+               origstack = gstack = guest_pa(lg, virtstack);
        }
 
        /* Remember that we never let the Guest actually disable interrupts, so
@@ -108,7 +113,7 @@ static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err)
        /* Now we've pushed all the old state, we change the stack, the code
         * segment and the address to execute. */
        lg->regs->ss = ss;
-       lg->regs->esp = gstack + lg->page_offset;
+       lg->regs->esp = virtstack + (gstack - origstack);
        lg->regs->cs = (__KERNEL_CS|GUEST_PL);
        lg->regs->eip = idt_address(lo, hi);