lguest: make hypercalls use the vcpu struct

this patch changes do_hcall() and do_async_hcall() interfaces (and obviously their
callers) to get a vcpu struct. Again, a vcpu services the hypercall, not the whole
guest

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

4 files changed, 44 insertions, 36 deletions

diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c
index 75b38f2c778a..0ea67cb0cc0b 100644
--- a/drivers/lguest/core.c
+++ b/drivers/lguest/core.c
@@ -181,8 +181,8 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
         /* We stop running once the Guest is dead. */
         while (!lg->dead) {
                 /* First we run any hypercalls the Guest wants done. */
-                if (lg->hcall)
-                        do_hypercalls(lg);
+                if (cpu->hcall)
+                        do_hypercalls(cpu);
 
                 /* It's possible the Guest did a NOTIFY hypercall to the
                  * Launcher, in which case we return from the read() now. */
@@ -234,7 +234,7 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
                 local_irq_enable();
 
                 /* Now we deal with whatever happened to the Guest. */
-                lguest_arch_handle_trap(lg);
+                lguest_arch_handle_trap(cpu);
         }
 
         if (lg->dead == ERR_PTR(-ERESTART))
diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
index 05fad6fa8049..7827671b2234 100644
--- a/drivers/lguest/hypercalls.c
+++ b/drivers/lguest/hypercalls.c
@@ -29,8 +29,10 @@
 
 /*H:120 This is the core hypercall routine: where the Guest gets what it wants.
  * Or gets killed.  Or, in the case of LHCALL_CRASH, both. */
-static void do_hcall(struct lguest *lg, struct hcall_args *args)
+static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 {
+        struct lguest *lg = cpu->lg;
+
         switch (args->arg0) {
         case LHCALL_FLUSH_ASYNC:
                 /* This call does nothing, except by breaking out of the Guest
@@ -93,7 +95,7 @@ static void do_hcall(struct lguest *lg, struct hcall_args *args)
                 break;
         default:
                 /* It should be an architecture-specific hypercall. */
-                if (lguest_arch_do_hcall(lg, args))
+                if (lguest_arch_do_hcall(cpu, args))
                         kill_guest(lg, "Bad hypercall %li\n", args->arg0);
         }
 }
@@ -106,10 +108,11 @@ static void do_hcall(struct lguest *lg, struct hcall_args *args)
  * Guest put them in the ring, but we also promise the Guest that they will
  * happen before any normal hypercall (which is why we check this before
  * checking for a normal hcall). */
-static void do_async_hcalls(struct lguest *lg)
+static void do_async_hcalls(struct lg_cpu *cpu)
 {
         unsigned int i;
         u8 st[LHCALL_RING_SIZE];
+        struct lguest *lg = cpu->lg;
 
         /* For simplicity, we copy the entire call status array in at once. */
         if (copy_from_user(&st, &lg->lguest_data->hcall_status, sizeof(st)))
@@ -121,7 +124,7 @@ static void do_async_hcalls(struct lguest *lg)
                 /* We remember where we were up to from last time.  This makes
                  * sure that the hypercalls are done in the order the Guest
                  * places them in the ring. */
-                unsigned int n = lg->next_hcall;
+                unsigned int n = cpu->next_hcall;
 
                 /* 0xFF means there's no call here (yet). */
                 if (st[n] == 0xFF)
@@ -129,8 +132,8 @@ static void do_async_hcalls(struct lguest *lg)
 
                 /* OK, we have hypercall.  Increment the "next_hcall" cursor,
                  * and wrap back to 0 if we reach the end. */
-                if (++lg->next_hcall == LHCALL_RING_SIZE)
-                        lg->next_hcall = 0;
+                if (++cpu->next_hcall == LHCALL_RING_SIZE)
+                        cpu->next_hcall = 0;
 
                 /* Copy the hypercall arguments into a local copy of
                  * the hcall_args struct. */
@@ -141,7 +144,7 @@ static void do_async_hcalls(struct lguest *lg)
                 }
 
                 /* Do the hypercall, same as a normal one. */
-                do_hcall(lg, &args);
+                do_hcall(cpu, &args);
 
                 /* Mark the hypercall done. */
                 if (put_user(0xFF, &lg->lguest_data->hcall_status[n])) {
@@ -158,16 +161,17 @@ static void do_async_hcalls(struct lguest *lg)
 
 /* Last of all, we look at what happens first of all.  The very first time the
  * Guest makes a hypercall, we end up here to set things up: */
-static void initialize(struct lguest *lg)
+static void initialize(struct lg_cpu *cpu)
 {
+        struct lguest *lg = cpu->lg;
         /* You can't do anything until you're initialized.  The Guest knows the
          * rules, so we're unforgiving here. */
-        if (lg->hcall->arg0 != LHCALL_LGUEST_INIT) {
-                kill_guest(lg, "hypercall %li before INIT", lg->hcall->arg0);
+        if (cpu->hcall->arg0 != LHCALL_LGUEST_INIT) {
+                kill_guest(lg, "hypercall %li before INIT", cpu->hcall->arg0);
                 return;
         }
 
-        if (lguest_arch_init_hypercalls(lg))
+        if (lguest_arch_init_hypercalls(cpu))
                 kill_guest(lg, "bad guest page %p", lg->lguest_data);
 
         /* The Guest tells us where we're not to deliver interrupts by putting
@@ -196,27 +200,27 @@ static void initialize(struct lguest *lg)
  * Remember from the Guest, hypercalls come in two flavors: normal and
  * asynchronous.  This file handles both of types.
  */
-void do_hypercalls(struct lguest *lg)
+void do_hypercalls(struct lg_cpu *cpu)
 {
         /* Not initialized yet?  This hypercall must do it. */
-        if (unlikely(!lg->lguest_data)) {
+        if (unlikely(!cpu->lg->lguest_data)) {
                 /* Set up the "struct lguest_data" */
-                initialize(lg);
+                initialize(cpu);
                 /* Hcall is done. */
-                lg->hcall = NULL;
+                cpu->hcall = NULL;
                 return;
         }
 
         /* The Guest has initialized.
          *
          * Look in the hypercall ring for the async hypercalls: */
-        do_async_hcalls(lg);
+        do_async_hcalls(cpu);
 
         /* If we stopped reading the hypercall ring because the Guest did a
          * NOTIFY to the Launcher, we want to return now.  Otherwise we do
          * the hypercall. */
-        if (!lg->pending_notify) {
-                do_hcall(lg, lg->hcall);
+        if (!cpu->lg->pending_notify) {
+                do_hcall(cpu, cpu->hcall);
                 /* Tricky point: we reset the hcall pointer to mark the
                  * hypercall as "done".  We use the hcall pointer rather than
                  * the trap number to indicate a hypercall is pending.
@@ -227,7 +231,7 @@ void do_hypercalls(struct lguest *lg)
                  * Launcher, the run_guest() loop will exit without running the
                  * Guest.  When it comes back it would try to re-run the
                  * hypercall. */
-                lg->hcall = NULL;
+                cpu->hcall = NULL;
         }
 }
 
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index bfca2716ad11..a4ebd415fa27 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -43,6 +43,10 @@ struct lguest;
 struct lg_cpu {
         unsigned int id;
         struct lguest *lg;
+
+        /* If a hypercall was asked for, this points to the arguments. */
+        struct hcall_args *hcall;
+        u32 next_hcall;
 };
 
 /* The private info the thread maintains about the guest. */
@@ -65,13 +69,9 @@ struct lguest
         u32 cr2;
         int halted;
         int ts;
-        u32 next_hcall;
         u32 esp1;
         u8 ss1;
 
-        /* If a hypercall was asked for, this points to the arguments. */
-        struct hcall_args *hcall;
-
         /* Do we need to stop what we're doing and return to userspace? */
         int break_out;
         wait_queue_head_t break_wq;
@@ -178,9 +178,9 @@ void page_table_guest_data_init(struct lguest *lg);
 void lguest_arch_host_init(void);
 void lguest_arch_host_fini(void);
 void lguest_arch_run_guest(struct lg_cpu *cpu);
-void lguest_arch_handle_trap(struct lguest *lg);
-int lguest_arch_init_hypercalls(struct lguest *lg);
-int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args);
+void lguest_arch_handle_trap(struct lg_cpu *cpu);
+int lguest_arch_init_hypercalls(struct lg_cpu *cpu);
+int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args);
 void lguest_arch_setup_regs(struct lguest *lg, unsigned long start);
 
 /* <arch>/switcher.S: */
@@ -191,7 +191,7 @@ int lguest_device_init(void);
 void lguest_device_remove(void);
 
 /* hypercalls.c: */
-void do_hypercalls(struct lguest *lg);
+void do_hypercalls(struct lg_cpu *cpu);
 void write_timestamp(struct lguest *lg);
 
 /*L:035
diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index 3d2131e169fd..5962160aff3d 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -283,8 +283,9 @@ static int emulate_insn(struct lguest *lg)
 }
 
 /*H:050 Once we've re-enabled interrupts, we look at why the Guest exited. */
-void lguest_arch_handle_trap(struct lguest *lg)
+void lguest_arch_handle_trap(struct lg_cpu *cpu)
 {
+        struct lguest *lg = cpu->lg;
         switch (lg->regs->trapnum) {
         case 13: /* We've intercepted a General Protection Fault. */
                 /* Check if this was one of those annoying IN or OUT
@@ -336,7 +337,7 @@ void lguest_arch_handle_trap(struct lguest *lg)
         case LGUEST_TRAP_ENTRY:
                 /* Our 'struct hcall_args' maps directly over our regs: we set
                  * up the pointer now to indicate a hypercall is pending. */
-                lg->hcall = (struct hcall_args *)lg->regs;
+                cpu->hcall = (struct hcall_args *)lg->regs;
                 return;
         }
 
@@ -491,8 +492,10 @@ void __exit lguest_arch_host_fini(void)
 
 
 /*H:122 The i386-specific hypercalls simply farm out to the right functions. */
-int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args)
+int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
 {
+        struct lguest *lg = cpu->lg;
+
         switch (args->arg0) {
         case LHCALL_LOAD_GDT:
                 load_guest_gdt(lg, args->arg1, args->arg2);
@@ -511,13 +514,14 @@ int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args)
 }
 
 /*H:126 i386-specific hypercall initialization: */
-int lguest_arch_init_hypercalls(struct lguest *lg)
+int lguest_arch_init_hypercalls(struct lg_cpu *cpu)
 {
         u32 tsc_speed;
+        struct lguest *lg = cpu->lg;
 
         /* The pointer to the Guest's "struct lguest_data" is the only
          * argument.  We check that address now. */
-        if (!lguest_address_ok(lg, lg->hcall->arg1, sizeof(*lg->lguest_data)))
+        if (!lguest_address_ok(lg, cpu->hcall->arg1, sizeof(*lg->lguest_data)))
                 return -EFAULT;
 
         /* Having checked it, we simply set lg->lguest_data to point straight
@@ -525,7 +529,7 @@ int lguest_arch_init_hypercalls(struct lguest *lg)
          * copy_to_user/from_user from now on, instead of lgread/write.  I put
          * this in to show that I'm not immune to writing stupid
          * optimizations. */
-        lg->lguest_data = lg->mem_base + lg->hcall->arg1;
+        lg->lguest_data = lg->mem_base + cpu->hcall->arg1;
 
         /* We insist that the Time Stamp Counter exist and doesn't change with
          * cpu frequency.  Some devious chip manufacturers decided that TSC