lguest: makes special fields be per-vcpu

lguest struct have room for some fields, namely, cr2, ts, esp1
and ss1, that are not really guest-wide, but rather, vcpu-wide.

This patch puts it in the vcpu struct

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

5 files changed, 36 insertions, 35 deletions

diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
index 83323b1cc0b..ab70bbebdf2 100644
--- a/drivers/lguest/hypercalls.c
+++ b/drivers/lguest/hypercalls.c
@@ -60,7 +60,7 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
                 /* FLUSH_TLB comes in two flavors, depending on the
                  * argument: */
                 if (args->arg1)
-                        guest_pagetable_clear_all(lg);
+                        guest_pagetable_clear_all(cpu);
                 else
                         guest_pagetable_flush_user(lg);
                 break;
@@ -68,10 +68,10 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
         /* All these calls simply pass the arguments through to the right
          * routines. */
         case LHCALL_NEW_PGTABLE:
-                guest_new_pagetable(lg, args->arg1);
+                guest_new_pagetable(cpu, args->arg1);
                 break;
         case LHCALL_SET_STACK:
-                guest_set_stack(lg, args->arg1, args->arg2, args->arg3);
+                guest_set_stack(cpu, args->arg1, args->arg2, args->arg3);
                 break;
         case LHCALL_SET_PTE:
                 guest_set_pte(lg, args->arg1, args->arg2, __pte(args->arg3));
@@ -84,7 +84,7 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
                 break;
         case LHCALL_TS:
                 /* This sets the TS flag, as we saw used in run_guest(). */
-                lg->ts = args->arg1;
+                cpu->ts = args->arg1;
                 break;
         case LHCALL_HALT:
                 /* Similarly, this sets the halted flag for run_guest(). */
@@ -191,7 +191,7 @@ static void initialize(struct lg_cpu *cpu)
          * first write to a Guest page.  This may have caused a copy-on-write
          * fault, but the old page might be (read-only) in the Guest
          * pagetable. */
-        guest_pagetable_clear_all(lg);
+        guest_pagetable_clear_all(cpu);
 }
 
 /*H:100
diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c
index 9c1c479e8c6..b87d9d6c36a 100644
--- a/drivers/lguest/interrupts_and_traps.c
+++ b/drivers/lguest/interrupts_and_traps.c
@@ -73,8 +73,8 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
         if ((cpu->regs->ss&0x3) != GUEST_PL) {
                 /* The Guest told us their kernel stack with the SET_STACK
                  * hypercall: both the virtual address and the segment */
-                virtstack = lg->esp1;
-                ss = lg->ss1;
+                virtstack = cpu->esp1;
+                ss = cpu->ss1;
 
                 origstack = gstack = guest_pa(lg, virtstack);
                 /* We push the old stack segment and pointer onto the new
@@ -311,10 +311,11 @@ static int direct_trap(unsigned int num)
  * the Guest.
  *
  * Which is deeply unfair, because (literally!) it wasn't the Guests' fault. */
-void pin_stack_pages(struct lguest *lg)
+void pin_stack_pages(struct lg_cpu *cpu)
 {
         unsigned int i;
 
+        struct lguest *lg = cpu->lg;
         /* Depending on the CONFIG_4KSTACKS option, the Guest can have one or
          * two pages of stack space. */
         for (i = 0; i < lg->stack_pages; i++)
@@ -322,7 +323,7 @@ void pin_stack_pages(struct lguest *lg)
                  * start of the page after the kernel stack.  Subtract one to
                  * get back onto the first stack page, and keep subtracting to
                  * get to the rest of the stack pages. */
-                pin_page(lg, lg->esp1 - 1 - i * PAGE_SIZE);
+                pin_page(lg, cpu->esp1 - 1 - i * PAGE_SIZE);
 }
 
 /* Direct traps also mean that we need to know whenever the Guest wants to use
@@ -333,21 +334,21 @@ void pin_stack_pages(struct lguest *lg)
  *
  * In Linux each process has its own kernel stack, so this happens a lot: we
  * change stacks on each context switch. */
-void guest_set_stack(struct lguest *lg, u32 seg, u32 esp, unsigned int pages)
+void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages)
 {
         /* You are not allowed have a stack segment with privilege level 0: bad
          * Guest! */
         if ((seg & 0x3) != GUEST_PL)
-                kill_guest(lg, "bad stack segment %i", seg);
+                kill_guest(cpu->lg, "bad stack segment %i", seg);
         /* We only expect one or two stack pages. */
         if (pages > 2)
-                kill_guest(lg, "bad stack pages %u", pages);
+                kill_guest(cpu->lg, "bad stack pages %u", pages);
         /* Save where the stack is, and how many pages */
-        lg->ss1 = seg;
-        lg->esp1 = esp;
-        lg->stack_pages = pages;
+        cpu->ss1 = seg;
+        cpu->esp1 = esp;
+        cpu->lg->stack_pages = pages;
         /* Make sure the new stack pages are mapped */
-        pin_stack_pages(lg);
+        pin_stack_pages(cpu);
 }
 
 /* All this reference to mapping stacks leads us neatly into the other complex
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index e7123fa6127..05637648a17 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -46,6 +46,11 @@ struct lg_cpu {
         struct task_struct *tsk;
         struct mm_struct *mm;   /* == tsk->mm, but that becomes NULL on exit */
 
+        u32 cr2;
+        int ts;
+        u32 esp1;
+        u8 ss1;
+
         /* At end of a page shared mapped over lguest_pages in guest.  */
         unsigned long regs_page;
         struct lguest_regs *regs;
@@ -80,10 +85,6 @@ struct lguest
          * memory in the Launcher. */
         void __user *mem_base;
         unsigned long kernel_address;
-        u32 cr2;
-        int ts;
-        u32 esp1;
-        u8 ss1;
 
         /* Bitmap of what has changed: see CHANGED_* above. */
         int changed;
@@ -141,8 +142,8 @@ void maybe_do_interrupt(struct lg_cpu *cpu);
 int deliver_trap(struct lg_cpu *cpu, unsigned int num);
 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 guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages);
+void pin_stack_pages(struct lg_cpu *cpu);
 void setup_default_idt_entries(struct lguest_ro_state *state,
                                const unsigned long *def);
 void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt,
@@ -164,9 +165,9 @@ 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);
 void free_guest_pagetable(struct lguest *lg);
-void guest_new_pagetable(struct lguest *lg, unsigned long pgtable);
+void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable);
 void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
-void guest_pagetable_clear_all(struct lguest *lg);
+void guest_pagetable_clear_all(struct lg_cpu *cpu);
 void guest_pagetable_flush_user(struct lguest *lg);
 void guest_set_pte(struct lguest *lg, unsigned long gpgdir,
                    unsigned long vaddr, pte_t val);
diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c
index f19add46994..e34c81636a8 100644
--- a/drivers/lguest/page_tables.c
+++ b/drivers/lguest/page_tables.c
@@ -432,9 +432,10 @@ static unsigned int new_pgdir(struct lguest *lg,
  * Now we've seen all the page table setting and manipulation, let's see what
  * what happens when the Guest changes page tables (ie. changes the top-level
  * pgdir).  This occurs on almost every context switch. */
-void guest_new_pagetable(struct lguest *lg, unsigned long pgtable)
+void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable)
 {
         int newpgdir, repin = 0;
+        struct lguest *lg = cpu->lg;
 
         /* Look to see if we have this one already. */
         newpgdir = find_pgdir(lg, pgtable);
@@ -446,7 +447,7 @@ void guest_new_pagetable(struct lguest *lg, unsigned long pgtable)
         lg->pgdidx = newpgdir;
         /* If it was completely blank, we map in the Guest kernel stack */
         if (repin)
-                pin_stack_pages(lg);
+                pin_stack_pages(cpu);
 }
 
 /*H:470 Finally, a routine which throws away everything: all PGD entries in all
@@ -468,11 +469,11 @@ static void release_all_pagetables(struct lguest *lg)
  * mapping.  Since kernel mappings are in every page table, it's easiest to
  * throw them all away.  This traps the Guest in amber for a while as
  * everything faults back in, but it's rare. */
-void guest_pagetable_clear_all(struct lguest *lg)
+void guest_pagetable_clear_all(struct lg_cpu *cpu)
 {
-        release_all_pagetables(lg);
+        release_all_pagetables(cpu->lg);
         /* We need the Guest kernel stack mapped again. */
-        pin_stack_pages(lg);
+        pin_stack_pages(cpu);
 }
 /*:*/
 /*M:009 Since we throw away all mappings when a kernel mapping changes, our
diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index e989b835886..65f2e380947 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -95,8 +95,8 @@ static void copy_in_guest_info(struct lg_cpu *cpu, struct lguest_pages *pages)
         /* Set up the two "TSS" members which tell the CPU what stack to use
          * for traps which do directly into the Guest (ie. traps at privilege
          * level 1). */
-        pages->state.guest_tss.esp1 = lg->esp1;
-        pages->state.guest_tss.ss1 = lg->ss1;
+        pages->state.guest_tss.esp1 = cpu->esp1;
+        pages->state.guest_tss.ss1 = cpu->ss1;
 
         /* Copy direct-to-Guest trap entries. */
         if (lg->changed & CHANGED_IDT)
@@ -165,12 +165,10 @@ static void run_guest_once(struct lg_cpu *cpu, struct lguest_pages *pages)
  * are disabled: we own the CPU. */
 void lguest_arch_run_guest(struct lg_cpu *cpu)
 {
-        struct lguest *lg = cpu->lg;
-
         /* Remember the awfully-named TS bit?  If the Guest has asked to set it
          * we set it now, so we can trap and pass that trap to the Guest if it
          * uses the FPU. */
-        if (lg->ts)
+        if (cpu->ts)
                 lguest_set_ts();
 
         /* SYSENTER is an optimized way of doing system calls.  We can't allow
@@ -325,7 +323,7 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
                 /* If the Guest doesn't want to know, we already restored the
                  * Floating Point Unit, so we just continue without telling
                  * it. */
-                if (!lg->ts)
+                if (!cpu->ts)
                         return;
                 break;
         case 32 ... 255: