Extend callback-registration hypercall to take a flags argument.

This can currently be used to request that event delivery be
disabled during callback processing.
Signed-off-by: Keir Fraser <keir@xensource.com>

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 7c6297b917458c289ebdf86b8e0aee86a4af0d97..189095691699e8a206dde8d2d599a4a661c7ca1d 100644 (file)
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -524,20 +524,29 @@ static void load_segments(struct vcpu *n)
     if ( unlikely(!all_segs_okay) )
     {
         struct cpu_user_regs *regs = guest_cpu_user_regs();
-        unsigned long   *rsp =
+        unsigned long *rsp =
             (n->arch.flags & TF_kernel_mode) ?
             (unsigned long *)regs->rsp :
             (unsigned long *)nctxt->kernel_sp;
+        unsigned long cs_and_mask, rflags;
 
         if ( !(n->arch.flags & TF_kernel_mode) )
             toggle_guest_mode(n);
         else
             regs->cs &= ~3;
 
+        /* CS longword also contains full evtchn_upcall_mask. */
+        cs_and_mask = (unsigned long)regs->cs |
+            ((unsigned long)n->vcpu_info->evtchn_upcall_mask << 32);
+
+        /* Fold upcall mask into RFLAGS.IF. */
+        rflags  = regs->rflags & ~X86_EFLAGS_IF;
+        rflags |= !n->vcpu_info->evtchn_upcall_mask << 9;
+
         if ( put_user(regs->ss,            rsp- 1) |
              put_user(regs->rsp,           rsp- 2) |
-             put_user(regs->rflags,        rsp- 3) |
-             put_user(regs->cs,            rsp- 4) |
+             put_user(rflags,              rsp- 3) |
+             put_user(cs_and_mask,         rsp- 4) |
              put_user(regs->rip,           rsp- 5) |
              put_user(nctxt->user_regs.gs, rsp- 6) |
              put_user(nctxt->user_regs.fs, rsp- 7) |
@@ -550,6 +559,10 @@ static void load_segments(struct vcpu *n)
             domain_crash(n->domain);
         }
 
+        if ( test_bit(_VGCF_failsafe_disables_events,
+                      &n->arch.guest_context.flags) )
+            n->vcpu_info->evtchn_upcall_mask = 1;
+
         regs->entry_vector  = TRAP_syscall;
         regs->rflags       &= 0xFFFCBEFFUL;
         regs->ss            = __GUEST_SS;

diff --git a/xen/arch/x86/x86_32/asm-offsets.c b/xen/arch/x86/x86_32/asm-offsets.c
index 07830746beb3d2035593e4bf1f52feb9b6d7fe9a..f03556ef8d16e25aaa4a847f9fe94a4bd360646e 100644 (file)
--- a/xen/arch/x86/x86_32/asm-offsets.c
+++ b/xen/arch/x86/x86_32/asm-offsets.c
@@ -64,11 +64,13 @@ void __dummy__(void)
            arch.guest_context.kernel_ss);
     OFFSET(VCPU_kernel_sp, struct vcpu,
            arch.guest_context.kernel_sp);
+    OFFSET(VCPU_guest_context_flags, struct vcpu, arch.guest_context.flags);
     OFFSET(VCPU_arch_guest_fpu_ctxt, struct vcpu, arch.guest_context.fpu_ctxt);
     OFFSET(VCPU_flags, struct vcpu, vcpu_flags);
     OFFSET(VCPU_nmi_addr, struct vcpu, nmi_addr);
     DEFINE(_VCPUF_nmi_pending, _VCPUF_nmi_pending);
     DEFINE(_VCPUF_nmi_masked, _VCPUF_nmi_masked);
+    DEFINE(_VGCF_failsafe_disables_events, _VGCF_failsafe_disables_events);
     BLANK();
 
     OFFSET(TSS_ss0, struct tss_struct, ss0);

diff --git a/xen/arch/x86/x86_32/entry.S b/xen/arch/x86/x86_32/entry.S
index 1a4ac5367e204659a84f674c53627f9daf6f2140..c0bc7e4e013e1d4b78a832afa6746fcf1873b161 100644 (file)
--- a/xen/arch/x86/x86_32/entry.S
+++ b/xen/arch/x86/x86_32/entry.S
@@ -130,7 +130,10 @@ failsafe_callback:
         movl  VCPU_failsafe_sel(%ebx),%eax
         movw  %ax,TRAPBOUNCE_cs(%edx)
         movw  $TBF_FAILSAFE,TRAPBOUNCE_flags(%edx)
-        call  create_bounce_frame
+        bt    $_VGCF_failsafe_disables_events,VCPU_guest_context_flags(%ebx)
+        jnc   1f
+        orw   $TBF_INTERRUPT,TRAPBOUNCE_flags(%edx)
+1:      call  create_bounce_frame
         xorl  %eax,%eax
         movl  %eax,UREGS_ds(%esp)
         movl  %eax,UREGS_es(%esp)

diff --git a/xen/arch/x86/x86_32/traps.c b/xen/arch/x86/x86_32/traps.c
index 64c038c4eefe195eda454ecfe5e1f14757a4ea5a..6fce183a17ce887beb0bac67847c41bd1f6e5ff4 100644 (file)
--- a/xen/arch/x86/x86_32/traps.c
+++ b/xen/arch/x86/x86_32/traps.c
@@ -346,6 +346,12 @@ static long register_guest_callback(struct callback_register *reg)
     case CALLBACKTYPE_failsafe:
         v->arch.guest_context.failsafe_callback_cs  = reg->address.cs;
         v->arch.guest_context.failsafe_callback_eip = reg->address.eip;
+        if ( reg->flags & CALLBACKF_mask_events )
+            set_bit(_VGCF_failsafe_disables_events,
+                    &v->arch.guest_context.flags);
+        else
+            clear_bit(_VGCF_failsafe_disables_events,
+                      &v->arch.guest_context.flags);
         break;
 
 #ifdef CONFIG_X86_SUPERVISOR_MODE_KERNEL

diff --git a/xen/arch/x86/x86_64/asm-offsets.c b/xen/arch/x86/x86_64/asm-offsets.c
index ebc3059a9cf242ad742525a6c4169b26bb9157b9..1719c50a050713debd98f8ed4ae15ab4235e8d0d 100644 (file)
--- a/xen/arch/x86/x86_64/asm-offsets.c
+++ b/xen/arch/x86/x86_64/asm-offsets.c
@@ -64,11 +64,14 @@ void __dummy__(void)
            arch.guest_context.syscall_callback_eip);
     OFFSET(VCPU_kernel_sp, struct vcpu,
            arch.guest_context.kernel_sp);
+    OFFSET(VCPU_guest_context_flags, struct vcpu, arch.guest_context.flags);
     OFFSET(VCPU_arch_guest_fpu_ctxt, struct vcpu, arch.guest_context.fpu_ctxt);
     OFFSET(VCPU_flags, struct vcpu, vcpu_flags);
     OFFSET(VCPU_nmi_addr, struct vcpu, nmi_addr);
     DEFINE(_VCPUF_nmi_pending, _VCPUF_nmi_pending);
     DEFINE(_VCPUF_nmi_masked, _VCPUF_nmi_masked);
+    DEFINE(_VGCF_failsafe_disables_events, _VGCF_failsafe_disables_events);
+    DEFINE(_VGCF_syscall_disables_events,  _VGCF_syscall_disables_events);
     BLANK();
 
     OFFSET(VCPU_svm_vmcb_pa, struct vcpu, arch.hvm_svm.vmcb_pa);

diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S
index 110c34a417150cc7057af4db0349d56392070dae..62bb86510b0a7f89d5bc622631bc07a0d256af6f 100644 (file)
--- a/xen/arch/x86/x86_64/entry.S
+++ b/xen/arch/x86/x86_64/entry.S
@@ -30,7 +30,10 @@ switch_to_kernel:
         movq  VCPU_syscall_addr(%rbx),%rax
         movq  %rax,TRAPBOUNCE_eip(%rdx)
         movw  $0,TRAPBOUNCE_flags(%rdx)
-        call  create_bounce_frame
+        bt    $_VGCF_syscall_disables_events,VCPU_guest_context_flags(%rbx)
+        jnc   1f
+        orw   $TBF_INTERRUPT,TRAPBOUNCE_flags(%rdx)
+1:      call  create_bounce_frame
         jmp   test_all_events
 
 /* %rbx: struct vcpu, interrupts disabled */
@@ -77,7 +80,10 @@ failsafe_callback:
         movq  VCPU_failsafe_addr(%rbx),%rax
         movq  %rax,TRAPBOUNCE_eip(%rdx)
         movw  $TBF_FAILSAFE,TRAPBOUNCE_flags(%rdx)
-        call  create_bounce_frame
+        bt    $_VGCF_failsafe_disables_events,VCPU_guest_context_flags(%rbx)
+        jnc   1f
+        orw   $TBF_INTERRUPT,TRAPBOUNCE_flags(%rdx)
+1:      call  create_bounce_frame
         jmp   test_all_events
 .previous
 .section __pre_ex_table,"a"

diff --git a/xen/arch/x86/x86_64/traps.c b/xen/arch/x86/x86_64/traps.c
index ad7c347182625178d9457e7cb2cdd9e97b993acc..8c11a5ef4f53ffd5cc74baf723c9372361c96895 100644 (file)
--- a/xen/arch/x86/x86_64/traps.c
+++ b/xen/arch/x86/x86_64/traps.c
@@ -334,10 +334,22 @@ static long register_guest_callback(struct callback_register *reg)
 
     case CALLBACKTYPE_failsafe:
         v->arch.guest_context.failsafe_callback_eip = reg->address;
+        if ( reg->flags & CALLBACKF_mask_events )
+            set_bit(_VGCF_failsafe_disables_events,
+                    &v->arch.guest_context.flags);
+        else
+            clear_bit(_VGCF_failsafe_disables_events,
+                      &v->arch.guest_context.flags);
         break;
 
     case CALLBACKTYPE_syscall:
         v->arch.guest_context.syscall_callback_eip  = reg->address;
+        if ( reg->flags & CALLBACKF_mask_events )
+            set_bit(_VGCF_syscall_disables_events,
+                    &v->arch.guest_context.flags);
+        else
+            clear_bit(_VGCF_syscall_disables_events,
+                      &v->arch.guest_context.flags);
         break;
 
     case CALLBACKTYPE_nmi:

diff --git a/xen/include/public/arch-x86_32.h b/xen/include/public/arch-x86_32.h
index 2a43ae53acda6b4673b98f17faffcc1c02cc0f11..c5237ca5c806893c8a2634724a8404a36df6dd40 100644 (file)
--- a/xen/include/public/arch-x86_32.h
+++ b/xen/include/public/arch-x86_32.h
@@ -138,9 +138,17 @@ typedef uint64_t tsc_timestamp_t; /* RDTSC timestamp */
 struct vcpu_guest_context {
     /* FPU registers come first so they can be aligned for FXSAVE/FXRSTOR. */
     struct { char x[512]; } fpu_ctxt;       /* User-level FPU registers     */
-#define VGCF_I387_VALID (1<<0)
-#define VGCF_HVM_GUEST  (1<<1)
-#define VGCF_IN_KERNEL  (1<<2)
+#define VGCF_I387_VALID                (1<<0)
+#define VGCF_HVM_GUEST                 (1<<1)
+#define VGCF_IN_KERNEL                 (1<<2)
+#define _VGCF_i387_valid               0
+#define VGCF_i387_valid                (1<<_VGCF_i387_valid)
+#define _VGCF_hvm_guest                1
+#define VGCF_hvm_guest                 (1<<_VGCF_hvm_guest)
+#define _VGCF_in_kernel                2
+#define VGCF_in_kernel                 (1<<_VGCF_in_kernel)
+#define _VGCF_failsafe_disables_events 3
+#define VGCF_failsafe_disables_events  (1<<_VGCF_failsafe_disables_events)
     unsigned long flags;                    /* VGCF_* flags                 */
     struct cpu_user_regs user_regs;         /* User-level CPU registers     */
     struct trap_info trap_ctxt[256];        /* Virtual IDT                  */

diff --git a/xen/include/public/arch-x86_64.h b/xen/include/public/arch-x86_64.h
index 0b0ca809ca90a8f71e9fedcfc3ef3ef9d795fc54..bea67d4b0c3d9c71b041b897a8e251fffa589eab 100644 (file)
--- a/xen/include/public/arch-x86_64.h
+++ b/xen/include/public/arch-x86_64.h
@@ -211,9 +211,19 @@ typedef uint64_t tsc_timestamp_t; /* RDTSC timestamp */
 struct vcpu_guest_context {
     /* FPU registers come first so they can be aligned for FXSAVE/FXRSTOR. */
     struct { char x[512]; } fpu_ctxt;       /* User-level FPU registers     */
-#define VGCF_I387_VALID (1<<0)
-#define VGCF_HVM_GUEST  (1<<1)
-#define VGCF_IN_KERNEL  (1<<2)
+#define VGCF_I387_VALID                (1<<0)
+#define VGCF_HVM_GUEST                 (1<<1)
+#define VGCF_IN_KERNEL                 (1<<2)
+#define _VGCF_i387_valid               0
+#define VGCF_i387_valid                (1<<_VGCF_i387_valid)
+#define _VGCF_hvm_guest                1
+#define VGCF_hvm_guest                 (1<<_VGCF_hvm_guest)
+#define _VGCF_in_kernel                2
+#define VGCF_in_kernel                 (1<<_VGCF_in_kernel)
+#define _VGCF_failsafe_disables_events 3
+#define VGCF_failsafe_disables_events  (1<<_VGCF_failsafe_disables_events)
+#define _VGCF_syscall_disables_events  4
+#define VGCF_syscall_disables_events   (1<<_VGCF_syscall_disables_events)
     unsigned long flags;                    /* VGCF_* flags                 */
     struct cpu_user_regs user_regs;         /* User-level CPU registers     */
     struct trap_info trap_ctxt[256];        /* Virtual IDT                  */

diff --git a/xen/include/public/callback.h b/xen/include/public/callback.h
index a9f4168dda7691e3668ea850e2e00d10f3e9e0d4..b497d99317f96942fb1484637c6396641db91dc0 100644 (file)
--- a/xen/include/public/callback.h
+++ b/xen/include/public/callback.h
@@ -28,13 +28,21 @@
 #define CALLBACKTYPE_sysenter              3
 #define CALLBACKTYPE_nmi                   4
 
+/*
+ * Disable event deliver during callback? This flag is ignored for event and
+ * NMI callbacks: event delivery is unconditionally disabled.
+ */
+#define _CALLBACKF_mask_events             0
+#define CALLBACKF_mask_events              (1U << _CALLBACKF_mask_events)
+
 /*
  * Register a callback.
  */
 #define CALLBACKOP_register                0
 struct callback_register {
-     int type;
-     xen_callback_t address;
+    uint16_t type;
+    uint16_t flags;
+    xen_callback_t address;
 };
 typedef struct callback_register callback_register_t;
 DEFINE_XEN_GUEST_HANDLE(callback_register_t);
@@ -47,7 +55,8 @@ DEFINE_XEN_GUEST_HANDLE(callback_register_t);
  */
 #define CALLBACKOP_unregister              1
 struct callback_unregister {
-     int type;
+    uint16_t type;
+    uint16_t _unused;
 };
 typedef struct callback_unregister callback_unregister_t;
 DEFINE_XEN_GUEST_HANDLE(callback_unregister_t);