diff --git a/Documentation/lguest/.gitignore b/Documentation/lguest/.gitignore new file mode 100644 index 0000000000000000000000000000000000000000..115587fd5f657941b57dfc46dfe95e779a912514 --- /dev/null +++ b/Documentation/lguest/.gitignore @@ -0,0 +1 @@ +lguest diff --git a/Documentation/lguest/lguest.txt b/Documentation/lguest/lguest.txt index 29510dc515109ad5dd8a16b5936f1f6086ae417c..28c747362f958162e70c5b092fad444d22e7d12e 100644 --- a/Documentation/lguest/lguest.txt +++ b/Documentation/lguest/lguest.txt @@ -3,11 +3,11 @@ /, /` - or, A Young Coder's Illustrated Hypervisor \\"--\\ http://lguest.ozlabs.org -Lguest is designed to be a minimal hypervisor for the Linux kernel, for -Linux developers and users to experiment with virtualization with the -minimum of complexity. Nonetheless, it should have sufficient -features to make it useful for specific tasks, and, of course, you are -encouraged to fork and enhance it (see drivers/lguest/README). +Lguest is designed to be a minimal 32-bit x86 hypervisor for the Linux kernel, +for Linux developers and users to experiment with virtualization with the +minimum of complexity. Nonetheless, it should have sufficient features to +make it useful for specific tasks, and, of course, you are encouraged to fork +and enhance it (see drivers/lguest/README). Features: @@ -37,6 +37,7 @@ Running Lguest: "Paravirtualized guest support" = Y "Lguest guest support" = Y "High Memory Support" = off/4GB + "PAE (Physical Address Extension) Support" = N "Alignment value to which kernel should be aligned" = 0x100000 (CONFIG_PARAVIRT=y, CONFIG_LGUEST_GUEST=y, CONFIG_HIGHMEM64G=n and CONFIG_PHYSICAL_ALIGN=0x100000) diff --git a/arch/x86/include/asm/lguest_hcall.h b/arch/x86/include/asm/lguest_hcall.h index 0f4ee7148afe2e0b7648ab8f89a544508bdf3309..faae1996487b7208b6314fd922f5e84a5cf9be4a 100644 --- a/arch/x86/include/asm/lguest_hcall.h +++ b/arch/x86/include/asm/lguest_hcall.h @@ -5,7 +5,6 @@ #define LHCALL_FLUSH_ASYNC 0 #define LHCALL_LGUEST_INIT 1 #define LHCALL_SHUTDOWN 2 -#define LHCALL_LOAD_GDT 3 #define LHCALL_NEW_PGTABLE 4 #define LHCALL_FLUSH_TLB 5 #define LHCALL_LOAD_IDT_ENTRY 6 @@ -17,6 +16,7 @@ #define LHCALL_SET_PMD 15 #define LHCALL_LOAD_TLS 16 #define LHCALL_NOTIFY 17 +#define LHCALL_LOAD_GDT_ENTRY 18 #define LGUEST_TRAP_ENTRY 0x1F diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index e94a11e42f9864a35e197d9fdf7919accc8ba095..a2085368a3dcd37b50037cc22bf1e82737a500ca 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -273,15 +273,15 @@ static void lguest_load_idt(const struct desc_ptr *desc) * controls the entire thing and the Guest asks it to make changes using the * LOAD_GDT hypercall. * - * This is the opposite of the IDT code where we have a LOAD_IDT_ENTRY - * hypercall and use that repeatedly to load a new IDT. I don't think it - * really matters, but wouldn't it be nice if they were the same? Wouldn't - * it be even better if you were the one to send the patch to fix it? + * This is the exactly like the IDT code. */ static void lguest_load_gdt(const struct desc_ptr *desc) { - BUG_ON((desc->size + 1) / 8 != GDT_ENTRIES); - kvm_hypercall2(LHCALL_LOAD_GDT, __pa(desc->address), GDT_ENTRIES); + unsigned int i; + struct desc_struct *gdt = (void *)desc->address; + + for (i = 0; i < (desc->size+1)/8; i++) + kvm_hypercall3(LHCALL_LOAD_GDT_ENTRY, i, gdt[i].a, gdt[i].b); } /* For a single GDT entry which changes, we do the lazy thing: alter our GDT, @@ -291,7 +291,9 @@ static void lguest_write_gdt_entry(struct desc_struct *dt, int entrynum, const void *desc, int type) { native_write_gdt_entry(dt, entrynum, desc, type); - kvm_hypercall2(LHCALL_LOAD_GDT, __pa(dt), GDT_ENTRIES); + /* Tell Host about this new entry. */ + kvm_hypercall3(LHCALL_LOAD_GDT_ENTRY, entrynum, + dt[entrynum].a, dt[entrynum].b); } /* OK, I lied. There are three "thread local storage" GDT entries which change diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h index ac8a4a3741b831e36d5ca499f85424e90b9d1335..af92a176697f379f1f8c345ceb1db061e3ac73b2 100644 --- a/drivers/lguest/lg.h +++ b/drivers/lguest/lg.h @@ -158,7 +158,8 @@ void free_interrupts(void); /* segments.c: */ void setup_default_gdt_entries(struct lguest_ro_state *state); void setup_guest_gdt(struct lg_cpu *cpu); -void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num); +void load_guest_gdt_entry(struct lg_cpu *cpu, unsigned int i, + u32 low, u32 hi); 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); diff --git a/drivers/lguest/segments.c b/drivers/lguest/segments.c index 4f15439b7f1288c8f0f9462e42e76db4471c199c..7ede64ffeef9e02b54ced2c2d024ccf17d9d59cd 100644 --- a/drivers/lguest/segments.c +++ b/drivers/lguest/segments.c @@ -144,18 +144,19 @@ void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt) 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 lg_cpu *cpu, unsigned long table, u32 num) +/*H:620 This is where the Guest asks us to load a new GDT entry + * (LHCALL_LOAD_GDT_ENTRY). We tweak the entry and copy it in. */ +void load_guest_gdt_entry(struct lg_cpu *cpu, u32 num, u32 lo, u32 hi) { /* 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(cpu->arch.gdt)) kill_guest(cpu, "too many gdt entries %i", num); - /* We read the whole thing in, then fix it up. */ - __lgread(cpu, cpu->arch.gdt, table, num * sizeof(cpu->arch.gdt[0])); - fixup_gdt_table(cpu, 0, ARRAY_SIZE(cpu->arch.gdt)); + /* Set it up, then fix it. */ + cpu->arch.gdt[num].a = lo; + cpu->arch.gdt[num].b = hi; + fixup_gdt_table(cpu, num, num+1); /* 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. */ cpu->changed |= CHANGED_GDT; diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c index a6b717644be0d50efc2f257e52e9e543cc545833..1a83910f674f031cded0dd302d485ad9e6804365 100644 --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -324,6 +324,11 @@ static void rewrite_hypercall(struct lg_cpu *cpu) u8 insn[3] = {0xcd, 0x1f, 0x90}; __lgwrite(cpu, guest_pa(cpu, cpu->regs->eip), insn, sizeof(insn)); + /* The above write might have caused a copy of that page to be made + * (if it was read-only). We need to make sure the Guest has + * up-to-date pagetables. As this doesn't happen often, we can just + * drop them all. */ + guest_pagetable_clear_all(cpu); } static bool is_hypercall(struct lg_cpu *cpu) @@ -563,8 +568,8 @@ void __exit lguest_arch_host_fini(void) int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args) { switch (args->arg0) { - case LHCALL_LOAD_GDT: - load_guest_gdt(cpu, args->arg1, args->arg2); + case LHCALL_LOAD_GDT_ENTRY: + load_guest_gdt_entry(cpu, args->arg1, args->arg2, args->arg3); break; case LHCALL_LOAD_IDT_ENTRY: load_guest_idt_entry(cpu, args->arg1, args->arg2, args->arg3); diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index 59268266b79a5b7c6b439c6e9b210bb25c4236a3..9c76a061a04dc7235ad689cea438fc8d0c6cfedf 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -190,7 +190,8 @@ static int balloon(void *_vballoon) try_to_freeze(); wait_event_interruptible(vb->config_change, (diff = towards_target(vb)) != 0 - || kthread_should_stop()); + || kthread_should_stop() + || freezing(current)); if (diff > 0) fill_balloon(vb, diff); else if (diff < 0)