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authorRusty Russell <rusty@rustcorp.com.au>2015-02-11 15:15:10 +1030
committerRusty Russell <rusty@rustcorp.com.au>2015-02-11 16:47:33 +1030
commit7313d5217e6b9817897172d6a6ff477bdc415ed6 (patch)
tree448fc79d9048af296aeb6c6fbbf5da84dc6f7046 /drivers/lguest/x86
parentd1c29465b8a52d8fc5a59aac92c6b206b69fe631 (diff)
lguest: add iomem region, where guest page faults get sent to userspace.
This lets us implement PCI. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/lguest/x86')
-rw-r--r--drivers/lguest/x86/core.c19
1 files changed, 18 insertions, 1 deletions
diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index 42e87bf14113..18d841e738bc 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -362,9 +362,19 @@ static void setup_emulate_insn(struct lg_cpu *cpu)
sizeof(cpu->pending.insn));
}
+static void setup_iomem_insn(struct lg_cpu *cpu, unsigned long iomem_addr)
+{
+ cpu->pending.trap = 14;
+ cpu->pending.addr = iomem_addr;
+ copy_from_guest(cpu, cpu->pending.insn, cpu->regs->eip,
+ sizeof(cpu->pending.insn));
+}
+
/*H:050 Once we've re-enabled interrupts, we look at why the Guest exited. */
void lguest_arch_handle_trap(struct lg_cpu *cpu)
{
+ unsigned long iomem_addr;
+
switch (cpu->regs->trapnum) {
case 13: /* We've intercepted a General Protection Fault. */
/* Hand to Launcher to emulate those pesky IN and OUT insns */
@@ -385,8 +395,15 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
* whether kernel or userspace code.
*/
if (demand_page(cpu, cpu->arch.last_pagefault,
- cpu->regs->errcode))
+ cpu->regs->errcode, &iomem_addr))
+ return;
+
+ /* Was this an access to memory mapped IO? */
+ if (iomem_addr) {
+ /* Tell Launcher, let it handle it. */
+ setup_iomem_insn(cpu, iomem_addr);
return;
+ }
/*
* OK, it's really not there (or not OK): the Guest needs to