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| author | Rusty Russell <rusty@rustcorp.com.au> | 2015-03-24 11:51:39 +1030 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2015-03-24 11:52:08 +1030 |
| commit | 2f921b5bb0511fb698681d8ef35c48be7a9116bf (patch) | |
| tree | e4f07e4d66f47c7af9142bf13e5851a77acec77f /drivers/lguest | |
| parent | 7042cb4eb30967b5eb9eeba04907882f04d6b6e5 (diff) | |
| download | linux-2f921b5bb0511fb698681d8ef35c48be7a9116bf.tar.gz linux-2f921b5bb0511fb698681d8ef35c48be7a9116bf.tar.bz2 linux-2f921b5bb0511fb698681d8ef35c48be7a9116bf.zip | |
lguest: suppress interrupts for single insn, not range.
The last patch reduced our interrupt-suppression region to one address,
so simplify the code somewhat.
Also, remove the obsolete undefined instruction ranges and the comment
which refers to lguest_guest.S instead of head_32.S.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/lguest')
| -rw-r--r-- | drivers/lguest/hypercalls.c | 5 | ||||
| -rw-r--r-- | drivers/lguest/interrupts_and_traps.c | 8 | ||||
| -rw-r--r-- | drivers/lguest/lg.h | 2 |
3 files changed, 7 insertions, 8 deletions
diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c index 1219af493c0f..19a32280731d 100644 --- a/drivers/lguest/hypercalls.c +++ b/drivers/lguest/hypercalls.c @@ -211,10 +211,9 @@ static void initialize(struct lg_cpu *cpu) /* * The Guest tells us where we're not to deliver interrupts by putting - * the range of addresses into "struct lguest_data". + * the instruction address into "struct lguest_data". */ - if (get_user(cpu->lg->noirq_start, &cpu->lg->lguest_data->noirq_start) - || get_user(cpu->lg->noirq_end, &cpu->lg->lguest_data->noirq_end)) + if (get_user(cpu->lg->noirq_iret, &cpu->lg->lguest_data->noirq_iret)) kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data); /* diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c index 70dfcdc29f1f..6d4c072b61e1 100644 --- a/drivers/lguest/interrupts_and_traps.c +++ b/drivers/lguest/interrupts_and_traps.c @@ -204,8 +204,7 @@ void try_deliver_interrupt(struct lg_cpu *cpu, unsigned int irq, bool more) * They may be in the middle of an iret, where they asked us never to * deliver interrupts. */ - if (cpu->regs->eip >= cpu->lg->noirq_start && - (cpu->regs->eip < cpu->lg->noirq_end)) + if (cpu->regs->eip == cpu->lg->noirq_iret) return; /* If they're halted, interrupts restart them. */ @@ -395,8 +394,9 @@ static bool direct_trap(unsigned int num) * The Guest has the ability to turn its interrupt gates into trap gates, * if it is careful. The Host will let trap gates can go directly to the * Guest, but the Guest needs the interrupts atomically disabled for an - * interrupt gate. It can do this by pointing the trap gate at instructions - * within noirq_start and noirq_end, where it can safely disable interrupts. + * interrupt gate. The Host could provide a mechanism to register more + * "no-interrupt" regions, and the Guest could point the trap gate at + * instructions within that region, where it can safely disable interrupts. */ /*M:006 diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h index 307e8b39e7d1..ac8ad0461e80 100644 --- a/drivers/lguest/lg.h +++ b/drivers/lguest/lg.h @@ -102,7 +102,7 @@ struct lguest { struct pgdir pgdirs[4]; - unsigned long noirq_start, noirq_end; + unsigned long noirq_iret; unsigned int stack_pages; u32 tsc_khz; |