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lguest: replace lguest_arch with lg_cpu_arch.
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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>
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Glauber de Oliveira Costa authored and rustyrussell committed Jan 30, 2008
1 parent a53a35a commit fc708b3
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Showing 5 changed files with 58 additions and 57 deletions.
28 changes: 14 additions & 14 deletions drivers/lguest/interrupts_and_traps.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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. */
Expand Down Expand Up @@ -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;
}

Expand Down Expand Up @@ -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. */
Expand All @@ -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
Expand Down Expand Up @@ -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;
Expand All @@ -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]);
Expand Down
19 changes: 10 additions & 9 deletions drivers/lguest/lg.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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. */
Expand Down Expand Up @@ -99,8 +101,6 @@ struct lguest

/* Dead? */
const char *dead;

struct lguest_arch arch;
};

extern struct mutex lguest_lock;
Expand Down Expand Up @@ -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);
Expand All @@ -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);
Expand Down
42 changes: 22 additions & 20 deletions drivers/lguest/segments.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;

Expand All @@ -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;
}
}

Expand Down Expand Up @@ -109,53 +109,54 @@ 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;

/* The default entries from setup_default_gdt_entries() are not
* 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;
Expand All @@ -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;
}
Expand Down
24 changes: 11 additions & 13 deletions drivers/lguest/x86/core.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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
Expand All @@ -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. */
Expand Down Expand Up @@ -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);
}

Expand Down Expand Up @@ -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! */
Expand Down Expand Up @@ -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);
}
2 changes: 1 addition & 1 deletion include/asm-x86/lguest.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -56,7 +56,7 @@ struct lguest_ro_state
struct desc_struct guest_gdt[GDT_ENTRIES];
};

struct lguest_arch
struct lg_cpu_arch
{
/* The GDT entries copied into lguest_ro_state when running. */
struct desc_struct gdt[GDT_ENTRIES];
Expand Down

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