[PATCH 14/16] makes special fields be per-vcpu

Glauber de Oliveira Costa
2008-01-07T13:11:00Z

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>
---
drivers/lguest/hypercalls.c | 10 +++++-----
drivers/lguest/interrupts_and_traps.c | 24 +++++++++++++-----------
drivers/lguest/lg.h | 18 ++++++++++--------
drivers/lguest/page_tables.c | 11 ++++++-----
drivers/lguest/x86/core.c | 10 ++++------
5 files changed, 38 insertions(+), 35 deletions(-)

diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
index edc8cb4..4a4133b 100644
--- a/drivers/lguest/hypercalls.c
+++ b/drivers/lguest/hypercalls.c
@@ -58,7 +58,7 @@ static void do_hcall(struct lg_vcpu *vcpu, 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(vcpu);
else
guest_pagetable_flush_user(lg);
break;
@@ -66,10 +66,10 @@ static void do_hcall(struct lg_vcpu *vcpu, 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(vcpu, args->arg1);
break;
case LHCALL_SET_STACK:
- guest_set_stack(lg, args->arg1, args->arg2, args->arg3);
+ guest_set_stack(vcpu, args->arg1, args->arg2, args->arg3);
break;
case LHCALL_SET_PTE:
guest_set_pte(lg, args->arg1, args->arg2, __pte(args->arg3));
@@ -82,7 +82,7 @@ static void do_hcall(struct lg_vcpu *vcpu, struct hcall_args *args)
break;
case LHCALL_TS:
/* This sets the TS flag, as we saw used in run_guest(). */
- lg->ts = args->arg1;
+ vcpu->ts = args->arg1;
break;
case LHCALL_HALT:
/* Similarly, this sets the halted flag for run_guest(). */
@@ -189,7 +189,7 @@ static void initialize(struct lg_vcpu *vcpu)
* 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(vcpu);
}

/*H:100
diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c
index c1ca198..745f3ae 100644
--- a/drivers/lguest/interrupts_and_traps.c
+++ b/drivers/lguest/interrupts_and_traps.c
@@ -74,8 +74,8 @@ static void set_guest_interrupt(struct lg_vcpu *vcpu, u32 lo, u32 hi,
if ((vcpu->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 = vcpu->esp1;
+ ss = vcpu->ss1;

origstack = gstack = guest_pa(lg, virtstack);
/* We push the old stack segment and pointer onto the new
@@ -313,10 +313,11 @@ 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_vcpu *vcpu)
{
unsigned int i;

+ struct lguest *lg = vcpu->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++)
@@ -324,7 +325,7 @@ 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, vcpu->esp1 - 1 - i * PAGE_SIZE);
}

/* Direct traps also mean that we need to know whenever the Guest wants to use
@@ -335,21 +336,22 @@ 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_vcpu *vcpu, 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(vcpu->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(vcpu->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;
+ vcpu->ss1 = seg;
+ vcpu->esp1 = esp;
+ vcpu->lg->stack_pages = pages;
/* Make sure the new stack pages are mapped */
- pin_stack_pages(lg);
+ pin_stack_pages(vcpu);
}

/* 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 8c9c8df..1b3c933 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -46,6 +46,11 @@ struct lg_vcpu {
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 +142,9 @@ void maybe_do_interrupt(struct lg_vcpu *vcpu);
int deliver_trap(struct lg_vcpu *vcpu, unsigned int num);
void load_guest_idt_entry(struct lg_vcpu *vcpu, 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_vcpu *vcpu, u32 seg, u32 esp,
+ unsigned int pages);
+void pin_stack_pages(struct lg_vcpu *vcpu);
void setup_default_idt_entries(struct lguest_ro_state *state,
const unsigned long *def);
void copy_traps(const struct lg_vcpu *vcpu, struct desc_struct *idt,
@@ -164,9 +166,9 @@ void copy_gdt_tls(const struct lg_vcpu *vcpu, 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_vcpu *vcpu, 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_vcpu *vcpu);
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 5045325..1a7ac3a 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_vcpu *vcpu, unsigned long pgtable)
{
int newpgdir, repin = 0;
+ struct lguest *lg = vcpu->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(vcpu);
}

/*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_vcpu *vcpu)
{
- release_all_pagetables(lg);
+ release_all_pagetables(vcpu->lg);
/* We need the Guest kernel stack mapped again. */
- pin_stack_pages(lg);
+ pin_stack_pages(vcpu);
}
/*:*/
/*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 edfac30..9a64174 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -96,8 +96,8 @@ static void copy_in_guest_info(struct lg_vcpu *vcpu,
/* 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 = vcpu->esp1;
+ pages->state.guest_tss.ss1 = vcpu->ss1;

/* Copy direct-to-Guest trap entries. */
if (lg->changed & CHANGED_IDT)
@@ -167,12 +167,10 @@ static void run_guest_once(struct lg_vcpu *vcpu,
* are disabled: we own the CPU. */
void lguest_arch_run_guest(struct lg_vcpu *vcpu)
{
- struct lguest *lg = vcpu->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 (vcpu->ts)
lguest_set_ts();

/* SYSENTER is an optimized way of doing system calls. We can't allow
@@ -328,7 +326,7 @@ void lguest_arch_handle_trap(struct lg_vcpu *vcpu)
/* 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 (!vcpu->ts)
return;
break;
case 32 ... 255:
--
1.5.0.6