KVM: MMU: unify slots_lock usage
Unify slots_lock acquision around vcpu_run(). This is simpler and less
error-prone.
Also fix some callsites that were not grabbing the lock properly.
[avi: drop slots_lock while in guest mode to avoid holding the lock
for indefinite periods]
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 32d9100..e6a38bf 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -201,7 +201,6 @@
int ret;
u64 pdpte[ARRAY_SIZE(vcpu->arch.pdptrs)];
- down_read(&vcpu->kvm->slots_lock);
ret = kvm_read_guest_page(vcpu->kvm, pdpt_gfn, pdpte,
offset * sizeof(u64), sizeof(pdpte));
if (ret < 0) {
@@ -218,7 +217,6 @@
memcpy(vcpu->arch.pdptrs, pdpte, sizeof(vcpu->arch.pdptrs));
out:
- up_read(&vcpu->kvm->slots_lock);
return ret;
}
@@ -233,13 +231,11 @@
if (is_long_mode(vcpu) || !is_pae(vcpu))
return false;
- down_read(&vcpu->kvm->slots_lock);
r = kvm_read_guest(vcpu->kvm, vcpu->arch.cr3 & ~31u, pdpte, sizeof(pdpte));
if (r < 0)
goto out;
changed = memcmp(pdpte, vcpu->arch.pdptrs, sizeof(pdpte)) != 0;
out:
- up_read(&vcpu->kvm->slots_lock);
return changed;
}
@@ -377,7 +373,6 @@
*/
}
- down_read(&vcpu->kvm->slots_lock);
/*
* Does the new cr3 value map to physical memory? (Note, we
* catch an invalid cr3 even in real-mode, because it would
@@ -393,7 +388,6 @@
vcpu->arch.cr3 = cr3;
vcpu->arch.mmu.new_cr3(vcpu);
}
- up_read(&vcpu->kvm->slots_lock);
}
EXPORT_SYMBOL_GPL(kvm_set_cr3);
@@ -503,7 +497,6 @@
version++;
- down_read(&kvm->slots_lock);
kvm_write_guest(kvm, wall_clock, &version, sizeof(version));
wc_ts = current_kernel_time();
@@ -515,7 +508,6 @@
version++;
kvm_write_guest(kvm, wall_clock, &version, sizeof(version));
- up_read(&kvm->slots_lock);
}
static void kvm_write_guest_time(struct kvm_vcpu *v)
@@ -609,10 +601,8 @@
vcpu->arch.hv_clock.tsc_shift = 22;
down_read(¤t->mm->mmap_sem);
- down_read(&vcpu->kvm->slots_lock);
vcpu->arch.time_page =
gfn_to_page(vcpu->kvm, data >> PAGE_SHIFT);
- up_read(&vcpu->kvm->slots_lock);
up_read(¤t->mm->mmap_sem);
if (is_error_page(vcpu->arch.time_page)) {
@@ -715,9 +705,11 @@
vcpu_load(vcpu);
+ down_read(&vcpu->kvm->slots_lock);
for (i = 0; i < msrs->nmsrs; ++i)
if (do_msr(vcpu, entries[i].index, &entries[i].data))
break;
+ up_read(&vcpu->kvm->slots_lock);
vcpu_put(vcpu);
@@ -1768,7 +1760,6 @@
void *data = val;
int r = X86EMUL_CONTINUE;
- down_read(&vcpu->kvm->slots_lock);
while (bytes) {
gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
unsigned offset = addr & (PAGE_SIZE-1);
@@ -1790,7 +1781,6 @@
addr += tocopy;
}
out:
- up_read(&vcpu->kvm->slots_lock);
return r;
}
EXPORT_SYMBOL_GPL(emulator_read_std);
@@ -1809,9 +1799,7 @@
return X86EMUL_CONTINUE;
}
- down_read(&vcpu->kvm->slots_lock);
gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
- up_read(&vcpu->kvm->slots_lock);
/* For APIC access vmexit */
if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
@@ -1844,7 +1832,7 @@
return X86EMUL_UNHANDLEABLE;
}
-int __emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
+int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
const void *val, int bytes)
{
int ret;
@@ -1856,17 +1844,6 @@
return 1;
}
-static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
- const void *val, int bytes)
-{
- int ret;
-
- down_read(&vcpu->kvm->slots_lock);
- ret =__emulator_write_phys(vcpu, gpa, val, bytes);
- up_read(&vcpu->kvm->slots_lock);
- return ret;
-}
-
static int emulator_write_emulated_onepage(unsigned long addr,
const void *val,
unsigned int bytes,
@@ -1875,9 +1852,7 @@
struct kvm_io_device *mmio_dev;
gpa_t gpa;
- down_read(&vcpu->kvm->slots_lock);
gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
- up_read(&vcpu->kvm->slots_lock);
if (gpa == UNMAPPED_GVA) {
kvm_inject_page_fault(vcpu, addr, 2);
@@ -1954,7 +1929,6 @@
char *kaddr;
u64 val;
- down_read(&vcpu->kvm->slots_lock);
gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
if (gpa == UNMAPPED_GVA ||
@@ -1974,9 +1948,8 @@
set_64bit((u64 *)(kaddr + offset_in_page(gpa)), val);
kunmap_atomic(kaddr, KM_USER0);
kvm_release_page_dirty(page);
- emul_write:
- up_read(&vcpu->kvm->slots_lock);
}
+emul_write:
#endif
return emulator_write_emulated(addr, new, bytes, vcpu);
@@ -2368,10 +2341,8 @@
kvm_x86_ops->skip_emulated_instruction(vcpu);
for (i = 0; i < nr_pages; ++i) {
- down_read(&vcpu->kvm->slots_lock);
page = gva_to_page(vcpu, address + i * PAGE_SIZE);
vcpu->arch.pio.guest_pages[i] = page;
- up_read(&vcpu->kvm->slots_lock);
if (!page) {
kvm_inject_gp(vcpu, 0);
free_pio_guest_pages(vcpu);
@@ -2445,7 +2416,9 @@
++vcpu->stat.halt_exits;
if (irqchip_in_kernel(vcpu->kvm)) {
vcpu->arch.mp_state = VCPU_MP_STATE_HALTED;
+ up_read(&vcpu->kvm->slots_lock);
kvm_vcpu_block(vcpu);
+ down_read(&vcpu->kvm->slots_lock);
if (vcpu->arch.mp_state != VCPU_MP_STATE_RUNNABLE)
return -EINTR;
return 1;
@@ -2738,6 +2711,7 @@
vcpu->arch.mp_state = VCPU_MP_STATE_RUNNABLE;
}
+ down_read(&vcpu->kvm->slots_lock);
vapic_enter(vcpu);
preempted:
@@ -2811,6 +2785,8 @@
kvm_lapic_sync_to_vapic(vcpu);
+ up_read(&vcpu->kvm->slots_lock);
+
vcpu->guest_mode = 1;
kvm_guest_enter();
@@ -2837,6 +2813,8 @@
preempt_enable();
+ down_read(&vcpu->kvm->slots_lock);
+
/*
* Profile KVM exit RIPs:
*/
@@ -2864,14 +2842,18 @@
}
out:
+ up_read(&vcpu->kvm->slots_lock);
if (r > 0) {
kvm_resched(vcpu);
+ down_read(&vcpu->kvm->slots_lock);
goto preempted;
}
post_kvm_run_save(vcpu, kvm_run);
+ down_read(&vcpu->kvm->slots_lock);
vapic_exit(vcpu);
+ up_read(&vcpu->kvm->slots_lock);
return r;
}
@@ -2906,9 +2888,12 @@
memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
vcpu->mmio_read_completed = 1;
vcpu->mmio_needed = 0;
+
+ down_read(&vcpu->kvm->slots_lock);
r = emulate_instruction(vcpu, kvm_run,
vcpu->arch.mmio_fault_cr2, 0,
EMULTYPE_NO_DECODE);
+ up_read(&vcpu->kvm->slots_lock);
if (r == EMULATE_DO_MMIO) {
/*
* Read-modify-write. Back to userspace.
@@ -3817,7 +3802,9 @@
void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
{
kvm_free_lapic(vcpu);
+ down_read(&vcpu->kvm->slots_lock);
kvm_mmu_destroy(vcpu);
+ up_read(&vcpu->kvm->slots_lock);
free_page((unsigned long)vcpu->arch.pio_data);
}