[PATCH v7 13/15] x86/hvm: use ioreq_t to track in-flight state

[Paul Durrant <paul.durrant@citrix.com>]

Use an ioreq_t rather than open coded state, size, dir and data fields
in struct hvm_vcpu_io. This also allows PIO completion to be handled
similarly to MMIO completion by re-issuing the handle_pio() call.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Keir Fraser <keir@xen.org>
Cc: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

v7:
- Modified struct field placement as knock-on from previous patch

v6:
- Added Andrew's reviewed-by

v5:
- Added missing hunk with call to handle_pio()
---
 xen/arch/x86/hvm/emulate.c       |   35 +++++++++++++++++++++--------------
 xen/arch/x86/hvm/hvm.c           |   13 +++++--------
 xen/arch/x86/hvm/svm/nestedsvm.c |    2 +-
 xen/arch/x86/hvm/vmx/realmode.c  |    4 ++--
 xen/include/asm-x86/hvm/vcpu.h   |   12 ++++--------
 5 files changed, 33 insertions(+), 33 deletions(-)

diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c
index 9d9219e..a2db826 100644
--- a/xen/arch/x86/hvm/emulate.c
+++ b/xen/arch/x86/hvm/emulate.c
@@ -91,6 +91,7 @@ static int hvmemul_do_io(
         .df = df,
         .data = data,
         .data_is_ptr = data_is_addr, /* ioreq_t field name is misleading */
+        .state = STATE_IOREQ_READY,
     };
     void *p_data = (void *)data;
     int rc;
@@ -128,12 +129,24 @@ static int hvmemul_do_io(
         }
     }
 
-    switch ( vio->io_state )
+    switch ( vio->io_req.state )
     {
     case STATE_IOREQ_NONE:
         break;
     case STATE_IORESP_READY:
-        vio->io_state = STATE_IOREQ_NONE;
+        vio->io_req.state = STATE_IOREQ_NONE;
+        p = vio->io_req;
+
+        /* Verify the emulation request has been correctly re-issued */
+        if ( (p.type != is_mmio ? IOREQ_TYPE_COPY : IOREQ_TYPE_PIO) ||
+             (p.addr != addr) ||
+             (p.size != size) ||
+             (p.count != reps) ||
+             (p.dir != dir) ||
+             (p.df != df) ||
+             (p.data_is_ptr != data_is_addr) )
+            domain_crash(curr->domain);
+
         if ( data_is_addr || dir == IOREQ_WRITE )
             return X86EMUL_UNHANDLEABLE;
         goto finish_access;
@@ -141,11 +154,6 @@ static int hvmemul_do_io(
         return X86EMUL_UNHANDLEABLE;
     }
 
-    vio->io_state = STATE_IOREQ_READY;
-    vio->io_size = size;
-    vio->io_dir = dir;
-    vio->io_data_is_addr = data_is_addr;
-
     if ( dir == IOREQ_WRITE )
     {
         if ( !data_is_addr )
@@ -154,13 +162,14 @@ static int hvmemul_do_io(
         hvmtrace_io_assist(&p);
     }
 
+    vio->io_req = p;
+
     rc = hvm_io_intercept(&p);
 
     switch ( rc )
     {
     case X86EMUL_OKAY:
-        vio->io_data = p.data;
-        vio->io_state = STATE_IOREQ_NONE;
+        vio->io_req.state = STATE_IOREQ_NONE;
         break;
     case X86EMUL_UNHANDLEABLE:
     {
@@ -171,15 +180,13 @@ static int hvmemul_do_io(
         if ( !s )
         {
             rc = hvm_process_io_intercept(&null_handler, &p);
-            if ( rc == X86EMUL_OKAY )
-                vio->io_data = p.data;
-            vio->io_state = STATE_IOREQ_NONE;
+            vio->io_req.state = STATE_IOREQ_NONE;
         }
         else
         {
             rc = hvm_send_assist_req(s, &p);
             if ( rc != X86EMUL_RETRY || curr->domain->is_shutting_down )
-                vio->io_state = STATE_IOREQ_NONE;
+                vio->io_req.state = STATE_IOREQ_NONE;
             else if ( data_is_addr || dir == IOREQ_WRITE )
                 rc = X86EMUL_OKAY;
         }
@@ -198,7 +205,7 @@ static int hvmemul_do_io(
         hvmtrace_io_assist(&p);
 
         if ( !data_is_addr )
-            memcpy(p_data, &vio->io_data, size);
+            memcpy(p_data, &p.data, size);
     }
 
     if ( is_mmio && !data_is_addr )
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 3be17f9..31ae4d4 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -421,11 +421,11 @@ static void hvm_io_assist(ioreq_t *p)
 
     if ( hvm_vcpu_io_need_completion(vio) )
     {
-        vio->io_state = STATE_IORESP_READY;
-        vio->io_data = p->data;
+        vio->io_req.state = STATE_IORESP_READY;
+        vio->io_req.data = p->data;
     }
     else
-        vio->io_state = STATE_IOREQ_NONE;
+        vio->io_req.state = STATE_IOREQ_NONE;
 
     msix_write_completion(curr);
     vcpu_end_shutdown_deferral(curr);
@@ -501,11 +501,8 @@ void hvm_do_resume(struct vcpu *v)
         handle_mmio();
         break;
     case HVMIO_pio_completion:
-        if ( vio->io_size == 4 ) /* Needs zero extension. */
-            guest_cpu_user_regs()->rax = (uint32_t)vio->io_data;
-        else
-            memcpy(&guest_cpu_user_regs()->rax, &vio->io_data, vio->io_size);
-        vio->io_state = STATE_IOREQ_NONE;
+        (void)handle_pio(vio->io_req.addr, vio->io_req.size,
+                         vio->io_req.dir);
         break;
     case HVMIO_realmode_completion:
     {
diff --git a/xen/arch/x86/hvm/svm/nestedsvm.c b/xen/arch/x86/hvm/svm/nestedsvm.c
index 2243873..2653bc1 100644
--- a/xen/arch/x86/hvm/svm/nestedsvm.c
+++ b/xen/arch/x86/hvm/svm/nestedsvm.c
@@ -1221,7 +1221,7 @@ enum hvm_intblk nsvm_intr_blocked(struct vcpu *v)
          * Delay the injection because this would result in delivering
          * an interrupt *within* the execution of an instruction.
          */
-        if ( v->arch.hvm_vcpu.hvm_io.io_state != STATE_IOREQ_NONE )
+        if ( v->arch.hvm_vcpu.hvm_io.io_req.state != STATE_IOREQ_NONE )
             return hvm_intblk_shadow;
 
         if ( !nv->nv_vmexit_pending && n2vmcb->exitintinfo.bytes != 0 ) {
diff --git a/xen/arch/x86/hvm/vmx/realmode.c b/xen/arch/x86/hvm/vmx/realmode.c
index 25533dc..e83a61f 100644
--- a/xen/arch/x86/hvm/vmx/realmode.c
+++ b/xen/arch/x86/hvm/vmx/realmode.c
@@ -205,7 +205,7 @@ void vmx_realmode(struct cpu_user_regs *regs)
 
         vmx_realmode_emulate_one(&hvmemul_ctxt);
 
-        if ( vio->io_state != STATE_IOREQ_NONE || vio->mmio_retry )
+        if ( vio->io_req.state != STATE_IOREQ_NONE || vio->mmio_retry )
             break;
 
         /* Stop emulating unless our segment state is not safe */
@@ -219,7 +219,7 @@ void vmx_realmode(struct cpu_user_regs *regs)
     }
 
     /* Need to emulate next time if we've started an IO operation */
-    if ( vio->io_state != STATE_IOREQ_NONE )
+    if ( vio->io_req.state != STATE_IOREQ_NONE )
         curr->arch.hvm_vmx.vmx_emulate = 1;
 
     if ( !curr->arch.hvm_vmx.vmx_emulate && !curr->arch.hvm_vmx.vmx_realmode )
diff --git a/xen/include/asm-x86/hvm/vcpu.h b/xen/include/asm-x86/hvm/vcpu.h
index 5c9faf2..01cbfe5 100644
--- a/xen/include/asm-x86/hvm/vcpu.h
+++ b/xen/include/asm-x86/hvm/vcpu.h
@@ -45,11 +45,7 @@ struct hvm_vcpu_asid {
 struct hvm_vcpu_io {
     /* I/O request in flight to device model. */
     enum hvm_io_completion io_completion;
-    unsigned long          io_data;
-    unsigned int           io_size;
-    uint8_t                io_state;
-    uint8_t                io_dir;
-    uint8_t                io_data_is_addr;
+    ioreq_t                io_req;
 
     /*
      * HVM emulation:
@@ -84,9 +80,9 @@ struct hvm_vcpu_io {
 
 static inline bool_t hvm_vcpu_io_need_completion(const struct hvm_vcpu_io *vio)
 {
-    return (vio->io_state == STATE_IOREQ_READY) &&
-           !vio->io_data_is_addr &&
-           (vio->io_dir == IOREQ_READ);
+    return (vio->io_req.state == STATE_IOREQ_READY) &&
+           !vio->io_req.data_is_ptr &&
+           (vio->io_req.dir == IOREQ_READ);
 }
 
 #define VMCX_EADDR    (~0ULL)
-- 
1.7.10.4