[HVM] Clean up IOREQ state managemnet and evtchn notifications.

Based on a patch from Xin Li <xin.b.li@intel.com>. Changed
significantly on the Xen side -- not as cut down as the original
patch: this one keeps the xen_event_channel 'API' unchanged.
Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/tools/ioemu/target-i386-dm/cpu.h b/tools/ioemu/target-i386-dm/cpu.h
index 8bc6c7bda954637d83ceea6332037c927ace2c4b..dc016edd3e0f9d4839ed3625079c9ea07ec06644 100644 (file)
--- a/tools/ioemu/target-i386-dm/cpu.h
+++ b/tools/ioemu/target-i386-dm/cpu.h
@@ -55,8 +55,6 @@ typedef struct CPUX86State {
     int interrupt_request;
 
     CPU_COMMON
-
-    int send_event;
 } CPUX86State;
 
 CPUX86State *cpu_x86_init(void);

diff --git a/tools/ioemu/target-i386-dm/helper2.c b/tools/ioemu/target-i386-dm/helper2.c
index 1948e01cdd338606a6671d57a38f14abb7f201c0..787d6631ac29e2009a1245096463e70438c37c13 100644 (file)
--- a/tools/ioemu/target-i386-dm/helper2.c
+++ b/tools/ioemu/target-i386-dm/helper2.c
@@ -506,10 +506,10 @@ void cpu_handle_ioreq(void *opaque)
 
         /* No state change if state = STATE_IORESP_HOOK */
         if (req->state == STATE_IOREQ_INPROCESS) {
-            mb();
             req->state = STATE_IORESP_READY;
-        }
-        env->send_event = 1;
+            xc_evtchn_notify(xce_handle, ioreq_local_port[send_vcpu]);
+        } else
+            destroy_hvm_domain();
     }
 }
 
@@ -526,8 +526,6 @@ int main_loop(void)
 
     qemu_set_fd_handler(evtchn_fd, cpu_handle_ioreq, NULL, env);
 
-    env->send_event = 0;
-
     while (1) {
         if (vm_running) {
             if (shutdown_requested)
@@ -540,11 +538,6 @@ int main_loop(void)
 
         /* Wait up to 10 msec. */
         main_loop_wait(10);
-
-        if (env->send_event) {
-            env->send_event = 0;
-            xc_evtchn_notify(xce_handle, ioreq_local_port[send_vcpu]);
-        }
     }
     destroy_hvm_domain();
     return 0;

diff --git a/xen/arch/ia64/vmx/vmx_support.c b/xen/arch/ia64/vmx/vmx_support.c
index 929d4edc9319c803c56b7f3d1f0e256e6de1be34..cdb4c51be0617823ff6a0a4b7b37a1e401e89075 100644 (file)
--- a/xen/arch/ia64/vmx/vmx_support.c
+++ b/xen/arch/ia64/vmx/vmx_support.c
@@ -49,7 +49,7 @@ void vmx_io_assist(struct vcpu *v)
     p = &vio->vp_ioreq;
 
     if (p->state == STATE_IORESP_READY) {
-        p->state = STATE_INVALID;
+        p->state = STATE_IOREQ_NONE;
     }
     else {
         /* Can't block here, for the same reason as other places to
@@ -65,7 +65,7 @@ void vmx_send_assist_req(struct vcpu *v)
     ioreq_t *p;
 
     p = &get_vio(v->domain, v->vcpu_id)->vp_ioreq;
-    if (unlikely(p->state != STATE_INVALID)) {
+    if (unlikely(p->state != STATE_IOREQ_NONE)) {
         /* This indicates a bug in the device model.  Crash the
            domain. */
         printk("Device model set bad IO state %d.\n", p->state);

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 1f4f3cb0de2d3986f8fb6cdddb6c06ff9fd79c1d..b3cabe5d0cf0e81c77f3a7b122318bf78d8885af 100644 (file)
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -60,10 +60,8 @@ struct hvm_function_table hvm_funcs;
 void hvm_stts(struct vcpu *v)
 {
     /* FPU state already dirty? Then no need to setup_fpu() lazily. */
-    if ( test_bit(_VCPUF_fpu_dirtied, &v->vcpu_flags) )
-        return;
-    
-    hvm_funcs.stts(v);
+    if ( !test_bit(_VCPUF_fpu_dirtied, &v->vcpu_flags) )
+        hvm_funcs.stts(v);
 }
 
 void hvm_set_guest_time(struct vcpu *v, u64 gtime)
@@ -79,34 +77,40 @@ void hvm_set_guest_time(struct vcpu *v, u64 gtime)
 void hvm_do_resume(struct vcpu *v)
 {
     ioreq_t *p;
-    struct periodic_time *pt =
-        &v->domain->arch.hvm_domain.pl_time.periodic_tm;
+    struct periodic_time *pt = &v->domain->arch.hvm_domain.pl_time.periodic_tm;
 
     hvm_stts(v);
 
-    /* pick up the elapsed PIT ticks and re-enable pit_timer */
-    if ( pt->enabled && v->vcpu_id == pt->bind_vcpu && pt->first_injected ) {
-        if ( v->arch.hvm_vcpu.guest_time ) {
+    /* Pick up the elapsed PIT ticks and re-enable pit_timer. */
+    if ( pt->enabled && (v->vcpu_id == pt->bind_vcpu) && pt->first_injected )
+    {
+        if ( v->arch.hvm_vcpu.guest_time )
+        {
             hvm_set_guest_time(v, v->arch.hvm_vcpu.guest_time);
             v->arch.hvm_vcpu.guest_time = 0;
         }
         pickup_deactive_ticks(pt);
     }
 
+    /* NB. Optimised for common case (p->state == STATE_IOREQ_NONE). */
     p = &get_vio(v->domain, v->vcpu_id)->vp_ioreq;
-    wait_on_xen_event_channel(v->arch.hvm_vcpu.xen_port,
-                              p->state != STATE_IOREQ_READY &&
-                              p->state != STATE_IOREQ_INPROCESS);
-    switch ( p->state )
+    while ( p->state != STATE_IOREQ_NONE )
     {
-    case STATE_IORESP_READY:
-        hvm_io_assist(v);
-        break;
-    case STATE_INVALID:
-        break;
-    default:
-        printk("Weird HVM iorequest state %d.\n", p->state);
-        domain_crash(v->domain);
+        switch ( p->state )
+        {
+        case STATE_IORESP_READY: /* IORESP_READY -> NONE */
+            hvm_io_assist(v);
+            break;
+        case STATE_IOREQ_READY:  /* IOREQ_{READY,INPROCESS} -> IORESP_READY */
+        case STATE_IOREQ_INPROCESS:
+            wait_on_xen_event_channel(v->arch.hvm_vcpu.xen_port,
+                                      (p->state != STATE_IOREQ_READY) &&
+                                      (p->state != STATE_IOREQ_INPROCESS));
+            break;
+        default:
+            gdprintk(XENLOG_ERR, "Weird HVM iorequest state %d.\n", p->state);
+            domain_crash_synchronous();
+        }
     }
 }
 

diff --git a/xen/arch/x86/hvm/io.c b/xen/arch/x86/hvm/io.c
index a56ac433311fa3a0205fdc6c4c1b667c10c29847..0e34be4ebb667d3448ab3720fce046c79f34904f 100644 (file)
--- a/xen/arch/x86/hvm/io.c
+++ b/xen/arch/x86/hvm/io.c
@@ -736,27 +736,25 @@ void hvm_io_assist(struct vcpu *v)
 
     io_opp = &v->arch.hvm_vcpu.io_op;
     regs   = &io_opp->io_context;
+    vio    = get_vio(v->domain, v->vcpu_id);
 
-    vio = get_vio(v->domain, v->vcpu_id);
-
-    if ( vio == 0 ) {
-        printk("bad shared page: %lx\n", (unsigned long)vio);
+    p = &vio->vp_ioreq;
+    if ( p->state != STATE_IORESP_READY )
+    {
+        gdprintk(XENLOG_ERR, "Unexpected HVM iorequest state %d.\n", p->state);
         domain_crash_synchronous();
     }
 
-    p = &vio->vp_ioreq;
+    p->state = STATE_IOREQ_NONE;
 
-    if ( p->state == STATE_IORESP_READY ) {
-        p->state = STATE_INVALID;
-        if ( p->type == IOREQ_TYPE_PIO )
-            hvm_pio_assist(regs, p, io_opp);
-        else
-            hvm_mmio_assist(regs, p, io_opp);
+    if ( p->type == IOREQ_TYPE_PIO )
+        hvm_pio_assist(regs, p, io_opp);
+    else
+        hvm_mmio_assist(regs, p, io_opp);
 
-        /* Copy register changes back into current guest state. */
-        hvm_load_cpu_guest_regs(v, regs);
-        memcpy(guest_cpu_user_regs(), regs, HVM_CONTEXT_STACK_BYTES);
-    }
+    /* Copy register changes back into current guest state. */
+    hvm_load_cpu_guest_regs(v, regs);
+    memcpy(guest_cpu_user_regs(), regs, HVM_CONTEXT_STACK_BYTES);
 }
 
 /*

diff --git a/xen/arch/x86/hvm/platform.c b/xen/arch/x86/hvm/platform.c
index 2fd21991b3d908bc9bbbe2e8943d64df1560a061..8246bc706a66a40f00006a16afae5dc52a05794d 100644 (file)
--- a/xen/arch/x86/hvm/platform.c
+++ b/xen/arch/x86/hvm/platform.c
@@ -727,7 +727,7 @@ static void hvm_send_assist_req(struct vcpu *v)
     ioreq_t *p;
 
     p = &get_vio(v->domain, v->vcpu_id)->vp_ioreq;
-    if ( unlikely(p->state != STATE_INVALID) ) {
+    if ( unlikely(p->state != STATE_IOREQ_NONE) ) {
         /* This indicates a bug in the device model.  Crash the
            domain. */
         printk("Device model set bad IO state %d.\n", p->state);
@@ -760,7 +760,7 @@ void send_pio_req(unsigned long port, unsigned long count, int size,
     }
 
     p = &vio->vp_ioreq;
-    if ( p->state != STATE_INVALID )
+    if ( p->state != STATE_IOREQ_NONE )
         printk("WARNING: send pio with something already pending (%d)?\n",
                p->state);
 
@@ -815,7 +815,7 @@ static void send_mmio_req(unsigned char type, unsigned long gpa,
 
     p = &vio->vp_ioreq;
 
-    if ( p->state != STATE_INVALID )
+    if ( p->state != STATE_IOREQ_NONE )
         printk("WARNING: send mmio with something already pending (%d)?\n",
                p->state);
     p->dir = dir;

diff --git a/xen/include/public/hvm/ioreq.h b/xen/include/public/hvm/ioreq.h
index 9c0f30ea7836266a88f5f21f6f5fc4a6af81c586..32aafa2534259d585ad53739e5a2e43153fc5554 100644 (file)
--- a/xen/include/public/hvm/ioreq.h
+++ b/xen/include/public/hvm/ioreq.h
@@ -27,7 +27,7 @@
 #define IOREQ_READ      1
 #define IOREQ_WRITE     0
 
-#define STATE_INVALID           0
+#define STATE_IOREQ_NONE        0
 #define STATE_IOREQ_READY       1
 #define STATE_IOREQ_INPROCESS   2
 #define STATE_IORESP_READY      3