diff options
Diffstat (limited to 'drivers/lguest')
| -rw-r--r-- | drivers/lguest/core.c | 1 | ||||
| -rw-r--r-- | drivers/lguest/interrupts_and_traps.c | 24 | ||||
| -rw-r--r-- | drivers/lguest/lguest_device.c | 22 | ||||
| -rw-r--r-- | drivers/lguest/page_tables.c | 25 | ||||
| -rw-r--r-- | drivers/lguest/x86/core.c | 4 |
5 files changed, 46 insertions, 30 deletions
diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c index 5eea4356d70..90663e01a56 100644 --- a/drivers/lguest/core.c +++ b/drivers/lguest/core.c @@ -135,6 +135,7 @@ static void unmap_switcher(void) /* Now we just need to free the pages we copied the switcher into */ for (i = 0; i < TOTAL_SWITCHER_PAGES; i++) __free_pages(switcher_page[i], 0); + kfree(switcher_page); } /*H:032 diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c index 0414ddf8758..a1039068f95 100644 --- a/drivers/lguest/interrupts_and_traps.c +++ b/drivers/lguest/interrupts_and_traps.c @@ -406,7 +406,8 @@ void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int num, u32 lo, u32 hi) * deliver_trap() to bounce it back into the Guest. */ static void default_idt_entry(struct desc_struct *idt, int trap, - const unsigned long handler) + const unsigned long handler, + const struct desc_struct *base) { /* A present interrupt gate. */ u32 flags = 0x8e00; @@ -415,6 +416,10 @@ static void default_idt_entry(struct desc_struct *idt, * the Guest to use the "int" instruction to trigger it. */ if (trap == LGUEST_TRAP_ENTRY) flags |= (GUEST_PL << 13); + else if (base) + /* Copy priv. level from what Guest asked for. This allows + * debug (int 3) traps from Guest userspace, for example. */ + flags |= (base->b & 0x6000); /* Now pack it into the IDT entry in its weird format. */ idt->a = (LGUEST_CS<<16) | (handler&0x0000FFFF); @@ -428,7 +433,7 @@ void setup_default_idt_entries(struct lguest_ro_state *state, unsigned int i; for (i = 0; i < ARRAY_SIZE(state->guest_idt); i++) - default_idt_entry(&state->guest_idt[i], i, def[i]); + default_idt_entry(&state->guest_idt[i], i, def[i], NULL); } /*H:240 We don't use the IDT entries in the "struct lguest" directly, instead @@ -442,6 +447,8 @@ void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt, /* 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(cpu->arch.idt); i++) { + const struct desc_struct *gidt = &cpu->arch.idt[i]; + /* If no Guest can ever override this trap, leave it alone. */ if (!direct_trap(i)) continue; @@ -449,12 +456,15 @@ void copy_traps(const struct lg_cpu *cpu, struct desc_struct *idt, /* Only trap gates (type 15) can go direct to the Guest. * 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(cpu->arch.idt[i].a, cpu->arch.idt[i].b) == 0xF) - idt[i] = cpu->arch.idt[i]; + * entries (type 0x0) also can't go direct, of course. + * + * If it can't go direct, we still need to copy the priv. level: + * they might want to give userspace access to a software + * interrupt. */ + if (idt_type(gidt->a, gidt->b) == 0xF) + idt[i] = *gidt; else - /* Reset it to the default. */ - default_idt_entry(&idt[i], i, def[i]); + default_idt_entry(&idt[i], i, def[i], gidt); } } diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c index 1a8de57289e..a661bbdae3d 100644 --- a/drivers/lguest/lguest_device.c +++ b/drivers/lguest/lguest_device.c @@ -98,16 +98,28 @@ static u32 lg_get_features(struct virtio_device *vdev) return features; } -static void lg_set_features(struct virtio_device *vdev, u32 features) +/* The virtio core takes the features the Host offers, and copies the + * ones supported by the driver into the vdev->features array. Once + * that's all sorted out, this routine is called so we can tell the + * Host which features we understand and accept. */ +static void lg_finalize_features(struct virtio_device *vdev) { - unsigned int i; + unsigned int i, bits; struct lguest_device_desc *desc = to_lgdev(vdev)->desc; /* Second half of bitmap is features we accept. */ u8 *out_features = lg_features(desc) + desc->feature_len; + /* Give virtio_ring a chance to accept features. */ + vring_transport_features(vdev); + + /* The vdev->feature array is a Linux bitmask: this isn't the + * same as a the simple array of bits used by lguest devices + * for features. So we do this slow, manual conversion which is + * completely general. */ memset(out_features, 0, desc->feature_len); - for (i = 0; i < min(desc->feature_len * 8, 32); i++) { - if (features & (1 << i)) + bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8; + for (i = 0; i < bits; i++) { + if (test_bit(i, vdev->features)) out_features[i / 8] |= (1 << (i % 8)); } } @@ -297,7 +309,7 @@ static void lg_del_vq(struct virtqueue *vq) /* The ops structure which hooks everything together. */ static struct virtio_config_ops lguest_config_ops = { .get_features = lg_get_features, - .set_features = lg_set_features, + .finalize_features = lg_finalize_features, .get = lg_get, .set = lg_set, .get_status = lg_get_status, diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c index d93500f24fb..81d0c605344 100644 --- a/drivers/lguest/page_tables.c +++ b/drivers/lguest/page_tables.c @@ -108,9 +108,8 @@ static unsigned long gpte_addr(pgd_t gpgd, unsigned long vaddr) } /*:*/ -/*M:014 get_pfn is slow; it takes the mmap sem and calls get_user_pages. We - * could probably try to grab batches of pages here as an optimization - * (ie. pre-faulting). :*/ +/*M:014 get_pfn is slow: we could probably try to grab batches of pages here as + * an optimization (ie. pre-faulting). :*/ /*H:350 This routine takes a page number given by the Guest and converts it to * an actual, physical page number. It can fail for several reasons: the @@ -123,19 +122,13 @@ static unsigned long gpte_addr(pgd_t gpgd, unsigned long vaddr) static unsigned long get_pfn(unsigned long virtpfn, int write) { struct page *page; - /* This value indicates failure. */ - unsigned long ret = -1UL; - /* get_user_pages() is a complex interface: it gets the "struct - * vm_area_struct" and "struct page" assocated with a range of pages. - * It also needs the task's mmap_sem held, and is not very quick. - * It returns the number of pages it got. */ - down_read(¤t->mm->mmap_sem); - if (get_user_pages(current, current->mm, virtpfn << PAGE_SHIFT, - 1, write, 1, &page, NULL) == 1) - ret = page_to_pfn(page); - up_read(¤t->mm->mmap_sem); - return ret; + /* gup me one page at this address please! */ + if (get_user_pages_fast(virtpfn << PAGE_SHIFT, 1, write, &page) == 1) + return page_to_pfn(page); + + /* This value indicates failure. */ + return -1UL; } /*H:340 Converting a Guest page table entry to a shadow (ie. real) page table @@ -174,7 +167,7 @@ static pte_t gpte_to_spte(struct lg_cpu *cpu, pte_t gpte, int write) /*H:460 And to complete the chain, release_pte() looks like this: */ static void release_pte(pte_t pte) { - /* Remember that get_user_pages() took a reference to the page, in + /* Remember that get_user_pages_fast() took a reference to the page, in * get_pfn()? We have to put it back now. */ if (pte_flags(pte) & _PAGE_PRESENT) put_page(pfn_to_page(pte_pfn(pte))); diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c index 95dfda52b4f..bf7942327bd 100644 --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -480,7 +480,7 @@ void __init lguest_arch_host_init(void) * bit on its CPU, depending on the argument (0 == unset). */ on_each_cpu(adjust_pge, (void *)0, 1); /* Turn off the feature in the global feature set. */ - clear_bit(X86_FEATURE_PGE, boot_cpu_data.x86_capability); + clear_cpu_cap(&boot_cpu_data, X86_FEATURE_PGE); } put_online_cpus(); }; @@ -491,7 +491,7 @@ void __exit lguest_arch_host_fini(void) /* If we had PGE before we started, turn it back on now. */ get_online_cpus(); if (cpu_had_pge) { - set_bit(X86_FEATURE_PGE, boot_cpu_data.x86_capability); + set_cpu_cap(&boot_cpu_data, X86_FEATURE_PGE); /* adjust_pge's argument "1" means set PGE. */ on_each_cpu(adjust_pge, (void *)1, 1); } |