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Merge branch 'kvm-updates/2.6.39' of git://git.kernel.org/pub/scm/vir…
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…t/kvm/kvm

* 'kvm-updates/2.6.39' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: move and fix substitue search for missing CPUID entries
  KVM: fix XSAVE bit scanning
  KVM: Enable async page fault processing
  KVM: fix crash on irqfd deassign
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torvalds committed Apr 7, 2011
2 parents ccfeef0 + bd22f5c commit 7bc30c2
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Showing 3 changed files with 50 additions and 12 deletions.
37 changes: 28 additions & 9 deletions arch/x86/kvm/x86.c
Original file line number Diff line number Diff line change
Expand Up @@ -2395,9 +2395,9 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
int i;

entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
for (i = 1; *nent < maxnent; ++i) {
if (entry[i - 1].eax == 0 && i != 2)
break;
for (i = 1; *nent < maxnent && i < 64; ++i) {
if (entry[i].eax == 0)
continue;
do_cpuid_1_ent(&entry[i], function, i);
entry[i].flags |=
KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
Expand Down Expand Up @@ -4958,12 +4958,6 @@ struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
best = e;
break;
}
/*
* Both basic or both extended?
*/
if (((e->function ^ function) & 0x80000000) == 0)
if (!best || e->function > best->function)
best = e;
}
return best;
}
Expand All @@ -4983,6 +4977,27 @@ int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
return 36;
}

/*
* If no match is found, check whether we exceed the vCPU's limit
* and return the content of the highest valid _standard_ leaf instead.
* This is to satisfy the CPUID specification.
*/
static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
u32 function, u32 index)
{
struct kvm_cpuid_entry2 *maxlevel;

maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
if (!maxlevel || maxlevel->eax >= function)
return NULL;
if (function & 0x80000000) {
maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
if (!maxlevel)
return NULL;
}
return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
}

void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
{
u32 function, index;
Expand All @@ -4995,6 +5010,10 @@ void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
kvm_register_write(vcpu, VCPU_REGS_RCX, 0);
kvm_register_write(vcpu, VCPU_REGS_RDX, 0);
best = kvm_find_cpuid_entry(vcpu, function, index);

if (!best)
best = check_cpuid_limit(vcpu, function, index);

if (best) {
kvm_register_write(vcpu, VCPU_REGS_RAX, best->eax);
kvm_register_write(vcpu, VCPU_REGS_RBX, best->ebx);
Expand Down
2 changes: 1 addition & 1 deletion virt/kvm/eventfd.c
Original file line number Diff line number Diff line change
Expand Up @@ -90,7 +90,7 @@ irqfd_shutdown(struct work_struct *work)
* We know no new events will be scheduled at this point, so block
* until all previously outstanding events have completed
*/
flush_work(&irqfd->inject);
flush_work_sync(&irqfd->inject);

/*
* It is now safe to release the object's resources
Expand Down
23 changes: 21 additions & 2 deletions virt/kvm/kvm_main.c
Original file line number Diff line number Diff line change
Expand Up @@ -1037,6 +1037,17 @@ static pfn_t get_fault_pfn(void)
return fault_pfn;
}

int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, int write, struct page **page)
{
int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET;

if (write)
flags |= FOLL_WRITE;

return __get_user_pages(tsk, mm, start, 1, flags, page, NULL, NULL);
}

static inline int check_user_page_hwpoison(unsigned long addr)
{
int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE;
Expand Down Expand Up @@ -1070,7 +1081,14 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic,
if (writable)
*writable = write_fault;

npages = get_user_pages_fast(addr, 1, write_fault, page);
if (async) {
down_read(&current->mm->mmap_sem);
npages = get_user_page_nowait(current, current->mm,
addr, write_fault, page);
up_read(&current->mm->mmap_sem);
} else
npages = get_user_pages_fast(addr, 1, write_fault,
page);

/* map read fault as writable if possible */
if (unlikely(!write_fault) && npages == 1) {
Expand All @@ -1093,7 +1111,8 @@ static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic,
return get_fault_pfn();

down_read(&current->mm->mmap_sem);
if (check_user_page_hwpoison(addr)) {
if (npages == -EHWPOISON ||
(!async && check_user_page_hwpoison(addr))) {
up_read(&current->mm->mmap_sem);
get_page(hwpoison_page);
return page_to_pfn(hwpoison_page);
Expand Down

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