[PATCH v15 14/19] pvh: Use PV handlers for PIO

[George Dunlap <george.dunlap@eu.citrix.com>]

Register an IO handler for the entire PIO range, and have it call the
PV PIO handlers.

NB at this point this won't do the full "copy and execute on the stack
with full GPRs" work-around; this may need to be sorted out for dom0 to allow
these instructions to happen in guest context.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
---

Note: PVH seems to work just fine without this patch (i.e., all PIOs
are noops).  Presumably something like this will be needed for dom0 at
some point.

CC: Mukesh Rathor <mukesh.rathor@oracle.com>
CC: Jan Beulich <jbeulich@suse.com>
CC: Tim Deegan <tim@xen.org>
CC: Keir Fraser <keir@xen.org>
CC: Jun Nakajima <jun.nakajima@intel.com>
CC: Eddie Dong <eddie.dong@intel.com>
---
 xen/arch/x86/hvm/hvm.c      |   18 ++++++++++++++++++
 xen/arch/x86/traps.c        |    4 ++--
 xen/include/asm-x86/traps.h |    8 ++++++++
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 3f245ba..fedbcde 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -519,6 +519,21 @@ static int hvm_print_line(
     return X86EMUL_OKAY;
 }
 
+static int handle_pvh_io(
+    int dir, uint32_t port, uint32_t bytes, uint32_t *val)
+{
+    struct vcpu *curr = current;
+    struct cpu_user_regs *regs = guest_cpu_user_regs();
+
+    if ( dir == IOREQ_WRITE )
+        guest_io_write(port, bytes, *val, curr, regs);
+    else
+        *val = guest_io_read(port, bytes, curr, regs);
+
+    return X86EMUL_OKAY;
+}
+
+
 int hvm_domain_initialise(struct domain *d)
 {
     int rc;
@@ -566,7 +581,10 @@ int hvm_domain_initialise(struct domain *d)
     d->arch.hvm_domain.io_handler->num_slot = 0;
 
     if ( is_pvh_domain(d) )
+    {
+        register_portio_handler(d, 0, 0xffffffff, handle_pvh_io);
         return 0;
+    }
 
     hvm_init_guest_time(d);
 
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 852b8e6..6c278bc 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1681,7 +1681,7 @@ static int pci_cfg_ok(struct domain *d, int write, int size)
     return 1;
 }
 
-static uint32_t guest_io_read(
+uint32_t guest_io_read(
     unsigned int port, unsigned int bytes,
     struct vcpu *v, struct cpu_user_regs *regs)
 {
@@ -1748,7 +1748,7 @@ static uint32_t guest_io_read(
     return data;
 }
 
-static void guest_io_write(
+void guest_io_write(
     unsigned int port, unsigned int bytes, uint32_t data,
     struct vcpu *v, struct cpu_user_regs *regs)
 {
diff --git a/xen/include/asm-x86/traps.h b/xen/include/asm-x86/traps.h
index 82cbcee..a26b318 100644
--- a/xen/include/asm-x86/traps.h
+++ b/xen/include/asm-x86/traps.h
@@ -49,4 +49,12 @@ extern int guest_has_trap_callback(struct domain *d, uint16_t vcpuid,
 extern int send_guest_trap(struct domain *d, uint16_t vcpuid,
 				unsigned int trap_nr);
 
+uint32_t guest_io_read(
+    unsigned int port, unsigned int bytes,
+    struct vcpu *v, struct cpu_user_regs *regs);
+void guest_io_write(
+    unsigned int port, unsigned int bytes, uint32_t data,
+    struct vcpu *v, struct cpu_user_regs *regs);
+
+
 #endif /* ASM_TRAP_H */
-- 
1.7.9.5