lguest: replace lguest_arch with lg_cpu_arch.

The fields found in lguest_arch are not really per-guest,
but per-cpu (gdt, idt, etc). So this patch turns lguest_arch
into lg_cpu_arch.

It makes sense to have a per-guest per-arch struct, but this
can be addressed later, when the need arrives.

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

4 files changed, 57 insertions, 56 deletions

diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c
index 468faf8233d6..306b93c71dcc 100644
--- a/drivers/lguest/interrupts_and_traps.c
+++ b/drivers/lguest/interrupts_and_traps.c
@@ -178,7 +178,7 @@ void maybe_do_interrupt(struct lg_cpu *cpu)
         /* Look at the IDT entry the Guest gave us for this interrupt.  The
          * first 32 (FIRST_EXTERNAL_VECTOR) entries are for traps, so we skip
          * over them. */
-        idt = &lg->arch.idt[FIRST_EXTERNAL_VECTOR+irq];
+        idt = &cpu->arch.idt[FIRST_EXTERNAL_VECTOR+irq];
         /* If they don't have a handler (yet?), we just ignore it */
         if (idt_present(idt->a, idt->b)) {
                 /* OK, mark it no longer pending and deliver it. */
@@ -251,15 +251,15 @@ int deliver_trap(struct lg_cpu *cpu, unsigned int num)
 {
         /* Trap numbers are always 8 bit, but we set an impossible trap number
          * for traps inside the Switcher, so check that here. */
-        if (num >= ARRAY_SIZE(cpu->lg->arch.idt))
+        if (num >= ARRAY_SIZE(cpu->arch.idt))
                 return 0;
 
         /* Early on the Guest hasn't set the IDT entries (or maybe it put a
          * bogus one in): if we fail here, the Guest will be killed. */
-        if (!idt_present(cpu->lg->arch.idt[num].a, cpu->lg->arch.idt[num].b))
+        if (!idt_present(cpu->arch.idt[num].a, cpu->arch.idt[num].b))
                 return 0;
-        set_guest_interrupt(cpu, cpu->lg->arch.idt[num].a,
-                            cpu->lg->arch.idt[num].b, has_err(num));
+        set_guest_interrupt(cpu, cpu->arch.idt[num].a,
+                            cpu->arch.idt[num].b, has_err(num));
         return 1;
 }
 
@@ -385,7 +385,7 @@ static void set_trap(struct lguest *lg, struct desc_struct *trap,
  *
  * We saw the Guest setting Interrupt Descriptor Table (IDT) entries with the
  * LHCALL_LOAD_IDT_ENTRY hypercall before: that comes here. */
-void load_guest_idt_entry(struct lguest *lg, unsigned int num, u32 lo, u32 hi)
+void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int num, u32 lo, u32 hi)
 {
         /* Guest never handles: NMI, doublefault, spurious interrupt or
          * hypercall.  We ignore when it tries to set them. */
@@ -394,13 +394,13 @@ void load_guest_idt_entry(struct lguest *lg, unsigned int num, u32 lo, u32 hi)
 
         /* Mark the IDT as changed: next time the Guest runs we'll know we have
          * to copy this again. */
-        lg->changed |= CHANGED_IDT;
+        cpu->lg->changed |= CHANGED_IDT;
 
         /* Check that the Guest doesn't try to step outside the bounds. */
-        if (num >= ARRAY_SIZE(lg->arch.idt))
-                kill_guest(lg, "Setting idt entry %u", num);
+        if (num >= ARRAY_SIZE(cpu->arch.idt))
+                kill_guest(cpu->lg, "Setting idt entry %u", num);
         else
-                set_trap(lg, &lg->arch.idt[num], num, lo, hi);
+                set_trap(cpu->lg, &cpu->arch.idt[num], num, lo, hi);
 }
 
 /* The default entry for each interrupt points into the Switcher routines which
@@ -436,14 +436,14 @@ void setup_default_idt_entries(struct lguest_ro_state *state,
 /*H:240 We don't use the IDT entries in the "struct lguest" directly, instead
  * we copy them into the IDT which we've set up for Guests on this CPU, just
  * before we run the Guest.  This routine does that copy. */
-void copy_traps(const struct lguest *lg, struct desc_struct *idt,
+void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt,
                 const unsigned long *def)
 {
         unsigned int i;
 
         /* We can simply copy the direct traps, otherwise we use the default
          * ones in the Switcher: they will return to the Host. */
-        for (i = 0; i < ARRAY_SIZE(lg->arch.idt); i++) {
+        for (i = 0; i < ARRAY_SIZE(cpu->arch.idt); i++) {
                 /* If no Guest can ever override this trap, leave it alone. */
                 if (!direct_trap(i))
                         continue;
@@ -452,8 +452,8 @@ void copy_traps(const struct lguest *lg, struct desc_struct *idt,
                  * Interrupt gates (type 14) disable interrupts as they are
                  * entered, which we never let the Guest do.  Not present
                  * entries (type 0x0) also can't go direct, of course. */
-                if (idt_type(lg->arch.idt[i].a, lg->arch.idt[i].b) == 0xF)
-                        idt[i] = lg->arch.idt[i];
+                if (idt_type(cpu->arch.idt[i].a, cpu->arch.idt[i].b) == 0xF)
+                        idt[i] = cpu->arch.idt[i];
                 else
                         /* Reset it to the default. */
                         default_idt_entry(&idt[i], i, def[i]);
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index 35b331230c55..d08b85342b92 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -57,6 +57,8 @@ struct lg_cpu {
 
         /* Pending virtual interrupts */
         DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
+
+        struct lg_cpu_arch arch;
 };
 
 /* The private info the thread maintains about the guest. */
@@ -99,8 +101,6 @@ struct lguest
 
         /* Dead? */
         const char *dead;
-
-        struct lguest_arch arch;
 };
 
 extern struct mutex lguest_lock;
@@ -139,12 +139,13 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user);
 /* interrupts_and_traps.c: */
 void maybe_do_interrupt(struct lg_cpu *cpu);
 int deliver_trap(struct lg_cpu *cpu, unsigned int num);
-void load_guest_idt_entry(struct lguest *lg, unsigned int i, u32 low, u32 hi);
+void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int i,
+                          u32 low, u32 hi);
 void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages);
 void pin_stack_pages(struct lguest *lg);
 void setup_default_idt_entries(struct lguest_ro_state *state,
                                const unsigned long *def);
-void copy_traps(const struct lguest *lg, struct desc_struct *idt,
+void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt,
                 const unsigned long *def);
 void guest_set_clockevent(struct lg_cpu *cpu, unsigned long delta);
 void init_clockdev(struct lg_cpu *cpu);
@@ -154,11 +155,11 @@ void free_interrupts(void);
 
 /* segments.c: */
 void setup_default_gdt_entries(struct lguest_ro_state *state);
-void setup_guest_gdt(struct lguest *lg);
-void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num);
-void guest_load_tls(struct lguest *lg, unsigned long tls_array);
-void copy_gdt(const struct lguest *lg, struct desc_struct *gdt);
-void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt);
+void setup_guest_gdt(struct lg_cpu *cpu);
+void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num);
+void guest_load_tls(struct lg_cpu *cpu, unsigned long tls_array);
+void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt);
+void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt);
 
 /* page_tables.c: */
 int init_guest_pagetable(struct lguest *lg, unsigned long pgtable);
diff --git a/drivers/lguest/segments.c b/drivers/lguest/segments.c
index 9e189cbec7dd..02138450ecf5 100644
--- a/drivers/lguest/segments.c
+++ b/drivers/lguest/segments.c
@@ -58,7 +58,7 @@ static int ignored_gdt(unsigned int num)
  * Protection Fault in the Switcher when it restores a Guest segment register
  * which tries to use that entry.  Then we kill the Guest for causing such a
  * mess: the message will be "unhandled trap 256". */
-static void fixup_gdt_table(struct lguest *lg, unsigned start, unsigned end)
+static void fixup_gdt_table(struct lg_cpu *cpu, unsigned start, unsigned end)
 {
         unsigned int i;
 
@@ -71,14 +71,14 @@ static void fixup_gdt_table(struct lguest *lg, unsigned start, unsigned end)
                 /* Segment descriptors contain a privilege level: the Guest is
                  * sometimes careless and leaves this as 0, even though it's
                  * running at privilege level 1.  If so, we fix it here. */
-                if ((lg->arch.gdt[i].b & 0x00006000) == 0)
-                        lg->arch.gdt[i].b |= (GUEST_PL << 13);
+                if ((cpu->arch.gdt[i].b & 0x00006000) == 0)
+                        cpu->arch.gdt[i].b |= (GUEST_PL << 13);
 
                 /* Each descriptor has an "accessed" bit.  If we don't set it
                  * now, the CPU will try to set it when the Guest first loads
                  * that entry into a segment register.  But the GDT isn't
                  * writable by the Guest, so bad things can happen. */
-                lg->arch.gdt[i].b |= 0x00000100;
+                cpu->arch.gdt[i].b |= 0x00000100;
         }
 }
 
@@ -109,31 +109,31 @@ void setup_default_gdt_entries(struct lguest_ro_state *state)
 
 /* This routine sets up the initial Guest GDT for booting.  All entries start
  * as 0 (unusable). */
-void setup_guest_gdt(struct lguest *lg)
+void setup_guest_gdt(struct lg_cpu *cpu)
 {
         /* Start with full 0-4G segments... */
-        lg->arch.gdt[GDT_ENTRY_KERNEL_CS] = FULL_EXEC_SEGMENT;
-        lg->arch.gdt[GDT_ENTRY_KERNEL_DS] = FULL_SEGMENT;
+        cpu->arch.gdt[GDT_ENTRY_KERNEL_CS] = FULL_EXEC_SEGMENT;
+        cpu->arch.gdt[GDT_ENTRY_KERNEL_DS] = FULL_SEGMENT;
         /* ...except the Guest is allowed to use them, so set the privilege
          * level appropriately in the flags. */
-        lg->arch.gdt[GDT_ENTRY_KERNEL_CS].b |= (GUEST_PL << 13);
-        lg->arch.gdt[GDT_ENTRY_KERNEL_DS].b |= (GUEST_PL << 13);
+        cpu->arch.gdt[GDT_ENTRY_KERNEL_CS].b |= (GUEST_PL << 13);
+        cpu->arch.gdt[GDT_ENTRY_KERNEL_DS].b |= (GUEST_PL << 13);
 }
 
 /*H:650 An optimization of copy_gdt(), for just the three "thead-local storage"
  * entries. */
-void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt)
+void copy_gdt_tls(const struct lg_cpu *cpu, struct desc_struct *gdt)
 {
         unsigned int i;
 
         for (i = GDT_ENTRY_TLS_MIN; i <= GDT_ENTRY_TLS_MAX; i++)
-                gdt[i] = lg->arch.gdt[i];
+                gdt[i] = cpu->arch.gdt[i];
 }
 
 /*H:640 When the Guest is run on a different CPU, or the GDT entries have
  * changed, copy_gdt() is called to copy the Guest's GDT entries across to this
  * CPU's GDT. */
-void copy_gdt(const struct lguest *lg, struct desc_struct *gdt)
+void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt)
 {
         unsigned int i;
 
@@ -141,21 +141,22 @@ void copy_gdt(const struct lguest *lg, struct desc_struct *gdt)
          * replaced.  See ignored_gdt() above. */
         for (i = 0; i < GDT_ENTRIES; i++)
                 if (!ignored_gdt(i))
-                        gdt[i] = lg->arch.gdt[i];
+                        gdt[i] = cpu->arch.gdt[i];
 }
 
 /*H:620 This is where the Guest asks us to load a new GDT (LHCALL_LOAD_GDT).
  * We copy it from the Guest and tweak the entries. */
-void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num)
+void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num)
 {
+        struct lguest *lg = cpu->lg;
         /* We assume the Guest has the same number of GDT entries as the
          * Host, otherwise we'd have to dynamically allocate the Guest GDT. */
-        if (num > ARRAY_SIZE(lg->arch.gdt))
+        if (num > ARRAY_SIZE(cpu->arch.gdt))
                 kill_guest(lg, "too many gdt entries %i", num);
 
         /* We read the whole thing in, then fix it up. */
-        __lgread(lg, lg->arch.gdt, table, num * sizeof(lg->arch.gdt[0]));
-        fixup_gdt_table(lg, 0, ARRAY_SIZE(lg->arch.gdt));
+        __lgread(lg, cpu->arch.gdt, table, num * sizeof(cpu->arch.gdt[0]));
+        fixup_gdt_table(cpu, 0, ARRAY_SIZE(cpu->arch.gdt));
         /* Mark that the GDT changed so the core knows it has to copy it again,
          * even if the Guest is run on the same CPU. */
         lg->changed |= CHANGED_GDT;
@@ -165,12 +166,13 @@ void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num)
  * Remember that this happens on every context switch, so it's worth
  * optimizing.  But wouldn't it be neater to have a single hypercall to cover
  * both cases? */
-void guest_load_tls(struct lguest *lg, unsigned long gtls)
+void guest_load_tls(struct lg_cpu *cpu, unsigned long gtls)
 {
-        struct desc_struct *tls = &lg->arch.gdt[GDT_ENTRY_TLS_MIN];
+        struct desc_struct *tls = &cpu->arch.gdt[GDT_ENTRY_TLS_MIN];
+        struct lguest *lg = cpu->lg;
 
         __lgread(lg, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES);
-        fixup_gdt_table(lg, GDT_ENTRY_TLS_MIN, GDT_ENTRY_TLS_MAX+1);
+        fixup_gdt_table(cpu, GDT_ENTRY_TLS_MIN, GDT_ENTRY_TLS_MAX+1);
         /* Note that just the TLS entries have changed. */
         lg->changed |= CHANGED_GDT_TLS;
 }
diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index d96a93d95aea..e989b8358864 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -100,14 +100,14 @@ static void copy_in_guest_info(struct lg_cpu *cpu, struct lguest_pages *pages)
 
         /* Copy direct-to-Guest trap entries. */
         if (lg->changed & CHANGED_IDT)
-                copy_traps(lg, pages->state.guest_idt, default_idt_entries);
+                copy_traps(cpu, pages->state.guest_idt, default_idt_entries);
 
         /* Copy all GDT entries which the Guest can change. */
         if (lg->changed & CHANGED_GDT)
-                copy_gdt(lg, pages->state.guest_gdt);
+                copy_gdt(cpu, pages->state.guest_gdt);
         /* If only the TLS entries have changed, copy them. */
         else if (lg->changed & CHANGED_GDT_TLS)
-                copy_gdt_tls(lg, pages->state.guest_gdt);
+                copy_gdt_tls(cpu, pages->state.guest_gdt);
 
         /* Mark the Guest as unchanged for next time. */
         lg->changed = 0;
@@ -196,7 +196,7 @@ void lguest_arch_run_guest(struct lg_cpu *cpu)
          * re-enable interrupts an interrupt could fault and thus overwrite
          * cr2, or we could even move off to a different CPU. */
         if (cpu->regs->trapnum == 14)
-                lg->arch.last_pagefault = read_cr2();
+                cpu->arch.last_pagefault = read_cr2();
         /* Similarly, if we took a trap because the Guest used the FPU,
          * we have to restore the FPU it expects to see. */
         else if (cpu->regs->trapnum == 7)
@@ -307,7 +307,7 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
                  *
                  * The errcode tells whether this was a read or a write, and
                  * whether kernel or userspace code. */
-                if (demand_page(lg, lg->arch.last_pagefault, cpu->regs->errcode))
+                if (demand_page(lg,cpu->arch.last_pagefault,cpu->regs->errcode))
                         return;
 
                 /* OK, it's really not there (or not OK): the Guest needs to
@@ -318,7 +318,7 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
                  * happen before it's done the LHCALL_LGUEST_INIT hypercall, so
                  * lg->lguest_data could be NULL */
                 if (lg->lguest_data &&
-                    put_user(lg->arch.last_pagefault, &lg->lguest_data->cr2))
+                    put_user(cpu->arch.last_pagefault, &lg->lguest_data->cr2))
                         kill_guest(lg, "Writing cr2");
                 break;
         case 7: /* We've intercepted a Device Not Available fault. */
@@ -349,7 +349,7 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
                  * it handle), it dies with a cryptic error message. */
                 kill_guest(lg, "unhandled trap %li at %#lx (%#lx)",
                            cpu->regs->trapnum, cpu->regs->eip,
-                           cpu->regs->trapnum == 14 ? lg->arch.last_pagefault
+                           cpu->regs->trapnum == 14 ? cpu->arch.last_pagefault
                            : cpu->regs->errcode);
 }
 
@@ -495,17 +495,15 @@ 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 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);
+                load_guest_gdt(cpu, args->arg1, args->arg2);
                 break;
         case LHCALL_LOAD_IDT_ENTRY:
-                load_guest_idt_entry(lg, args->arg1, args->arg2, args->arg3);
+                load_guest_idt_entry(cpu, args->arg1, args->arg2, args->arg3);
                 break;
         case LHCALL_LOAD_TLS:
-                guest_load_tls(lg, args->arg1);
+                guest_load_tls(cpu, args->arg1);
                 break;
         default:
                 /* Bad Guest.  Bad! */
@@ -586,5 +584,5 @@ void lguest_arch_setup_regs(struct lg_cpu *cpu, unsigned long start)
 
         /* There are a couple of GDT entries the Guest expects when first
          * booting. */
-        setup_guest_gdt(cpu->lg);
+        setup_guest_gdt(cpu);
 }