forked from Minki/linux
KVM: PPC: Book3S HV: Refactor radix page fault handler
The radix page fault handler accounts for all cases, including just needing to insert a pte. This breaks it up into separate functions for the two main cases; setting rc and inserting a pte. This allows us to make the setting of rc and inserting of a pte generic for any pgtable, not specific to the one for this guest. [paulus@ozlabs.org - reduced diffs from previous code] Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Suraj Jitindar Singh
Michael Ellerman
parent
9811c78e96
commit
04bae9d5b4
@ -400,8 +400,9 @@ static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud,
|
||||
*/
|
||||
#define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED))
|
||||
|
||||
static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
|
||||
unsigned int level, unsigned long mmu_seq)
|
||||
static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
|
||||
unsigned long gpa, unsigned int level,
|
||||
unsigned long mmu_seq)
|
||||
{
|
||||
pgd_t *pgd;
|
||||
pud_t *pud, *new_pud = NULL;
|
||||
@ -410,7 +411,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
|
||||
int ret;
|
||||
|
||||
/* Traverse the guest's 2nd-level tree, allocate new levels needed */
|
||||
pgd = kvm->arch.pgtable + pgd_index(gpa);
|
||||
pgd = pgtable + pgd_index(gpa);
|
||||
pud = NULL;
|
||||
if (pgd_present(*pgd))
|
||||
pud = pud_offset(pgd, gpa);
|
||||
@ -565,95 +566,49 @@ static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
|
||||
return ret;
|
||||
}
|
||||
|
||||
int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
|
||||
unsigned long ea, unsigned long dsisr)
|
||||
static bool kvmppc_hv_handle_set_rc(struct kvm *kvm, pgd_t *pgtable,
|
||||
bool writing, unsigned long gpa)
|
||||
{
|
||||
unsigned long pgflags;
|
||||
unsigned int shift;
|
||||
pte_t *ptep;
|
||||
|
||||
/*
|
||||
* Need to set an R or C bit in the 2nd-level tables;
|
||||
* since we are just helping out the hardware here,
|
||||
* it is sufficient to do what the hardware does.
|
||||
*/
|
||||
pgflags = _PAGE_ACCESSED;
|
||||
if (writing)
|
||||
pgflags |= _PAGE_DIRTY;
|
||||
/*
|
||||
* We are walking the secondary (partition-scoped) page table here.
|
||||
* We can do this without disabling irq because the Linux MM
|
||||
* subsystem doesn't do THP splits and collapses on this tree.
|
||||
*/
|
||||
ptep = __find_linux_pte(pgtable, gpa, NULL, &shift);
|
||||
if (ptep && pte_present(*ptep) && (!writing || pte_write(*ptep))) {
|
||||
kvmppc_radix_update_pte(kvm, ptep, 0, pgflags, gpa, shift);
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
static int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu,
|
||||
unsigned long gpa,
|
||||
struct kvm_memory_slot *memslot,
|
||||
bool writing, bool kvm_ro,
|
||||
pte_t *inserted_pte, unsigned int *levelp)
|
||||
{
|
||||
struct kvm *kvm = vcpu->kvm;
|
||||
unsigned long mmu_seq;
|
||||
unsigned long gpa, gfn, hva;
|
||||
struct kvm_memory_slot *memslot;
|
||||
struct page *page = NULL;
|
||||
long ret;
|
||||
bool writing;
|
||||
unsigned long mmu_seq;
|
||||
unsigned long hva, gfn = gpa >> PAGE_SHIFT;
|
||||
bool upgrade_write = false;
|
||||
bool *upgrade_p = &upgrade_write;
|
||||
pte_t pte, *ptep;
|
||||
unsigned long pgflags;
|
||||
unsigned int shift, level;
|
||||
|
||||
/* Check for unusual errors */
|
||||
if (dsisr & DSISR_UNSUPP_MMU) {
|
||||
pr_err("KVM: Got unsupported MMU fault\n");
|
||||
return -EFAULT;
|
||||
}
|
||||
if (dsisr & DSISR_BADACCESS) {
|
||||
/* Reflect to the guest as DSI */
|
||||
pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
|
||||
kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
|
||||
return RESUME_GUEST;
|
||||
}
|
||||
|
||||
/* Translate the logical address and get the page */
|
||||
gpa = vcpu->arch.fault_gpa & ~0xfffUL;
|
||||
gpa &= ~0xF000000000000000ul;
|
||||
gfn = gpa >> PAGE_SHIFT;
|
||||
if (!(dsisr & DSISR_PRTABLE_FAULT))
|
||||
gpa |= ea & 0xfff;
|
||||
memslot = gfn_to_memslot(kvm, gfn);
|
||||
|
||||
/* No memslot means it's an emulated MMIO region */
|
||||
if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
|
||||
if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS |
|
||||
DSISR_SET_RC)) {
|
||||
/*
|
||||
* Bad address in guest page table tree, or other
|
||||
* unusual error - reflect it to the guest as DSI.
|
||||
*/
|
||||
kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
|
||||
return RESUME_GUEST;
|
||||
}
|
||||
return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
|
||||
dsisr & DSISR_ISSTORE);
|
||||
}
|
||||
|
||||
writing = (dsisr & DSISR_ISSTORE) != 0;
|
||||
if (memslot->flags & KVM_MEM_READONLY) {
|
||||
if (writing) {
|
||||
/* give the guest a DSI */
|
||||
dsisr = DSISR_ISSTORE | DSISR_PROTFAULT;
|
||||
kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
|
||||
return RESUME_GUEST;
|
||||
}
|
||||
upgrade_p = NULL;
|
||||
}
|
||||
|
||||
if (dsisr & DSISR_SET_RC) {
|
||||
/*
|
||||
* Need to set an R or C bit in the 2nd-level tables;
|
||||
* since we are just helping out the hardware here,
|
||||
* it is sufficient to do what the hardware does.
|
||||
*/
|
||||
pgflags = _PAGE_ACCESSED;
|
||||
if (writing)
|
||||
pgflags |= _PAGE_DIRTY;
|
||||
/*
|
||||
* We are walking the secondary page table here. We can do this
|
||||
* without disabling irq.
|
||||
*/
|
||||
spin_lock(&kvm->mmu_lock);
|
||||
ptep = __find_linux_pte(kvm->arch.pgtable,
|
||||
gpa, NULL, &shift);
|
||||
if (ptep && pte_present(*ptep) &&
|
||||
(!writing || pte_write(*ptep))) {
|
||||
kvmppc_radix_update_pte(kvm, ptep, 0, pgflags,
|
||||
gpa, shift);
|
||||
dsisr &= ~DSISR_SET_RC;
|
||||
}
|
||||
spin_unlock(&kvm->mmu_lock);
|
||||
if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
|
||||
DSISR_PROTFAULT | DSISR_SET_RC)))
|
||||
return RESUME_GUEST;
|
||||
}
|
||||
int ret;
|
||||
|
||||
/* used to check for invalidations in progress */
|
||||
mmu_seq = kvm->mmu_notifier_seq;
|
||||
@ -666,7 +621,7 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
|
||||
* is that the page is writable.
|
||||
*/
|
||||
hva = gfn_to_hva_memslot(memslot, gfn);
|
||||
if (upgrade_p && __get_user_pages_fast(hva, 1, 1, &page) == 1) {
|
||||
if (!kvm_ro && __get_user_pages_fast(hva, 1, 1, &page) == 1) {
|
||||
upgrade_write = true;
|
||||
} else {
|
||||
unsigned long pfn;
|
||||
@ -724,7 +679,12 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
|
||||
}
|
||||
|
||||
/* Allocate space in the tree and write the PTE */
|
||||
ret = kvmppc_create_pte(kvm, pte, gpa, level, mmu_seq);
|
||||
ret = kvmppc_create_pte(kvm, kvm->arch.pgtable, pte, gpa, level,
|
||||
mmu_seq);
|
||||
if (inserted_pte)
|
||||
*inserted_pte = pte;
|
||||
if (levelp)
|
||||
*levelp = level;
|
||||
|
||||
if (page) {
|
||||
if (!ret && (pte_val(pte) & _PAGE_WRITE))
|
||||
@ -732,6 +692,82 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
|
||||
put_page(page);
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
|
||||
unsigned long ea, unsigned long dsisr)
|
||||
{
|
||||
struct kvm *kvm = vcpu->kvm;
|
||||
unsigned long gpa, gfn;
|
||||
struct kvm_memory_slot *memslot;
|
||||
long ret;
|
||||
bool writing = !!(dsisr & DSISR_ISSTORE);
|
||||
bool kvm_ro = false;
|
||||
|
||||
/* Check for unusual errors */
|
||||
if (dsisr & DSISR_UNSUPP_MMU) {
|
||||
pr_err("KVM: Got unsupported MMU fault\n");
|
||||
return -EFAULT;
|
||||
}
|
||||
if (dsisr & DSISR_BADACCESS) {
|
||||
/* Reflect to the guest as DSI */
|
||||
pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
|
||||
kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
|
||||
return RESUME_GUEST;
|
||||
}
|
||||
|
||||
/* Translate the logical address */
|
||||
gpa = vcpu->arch.fault_gpa & ~0xfffUL;
|
||||
gpa &= ~0xF000000000000000ul;
|
||||
gfn = gpa >> PAGE_SHIFT;
|
||||
if (!(dsisr & DSISR_PRTABLE_FAULT))
|
||||
gpa |= ea & 0xfff;
|
||||
|
||||
/* Get the corresponding memslot */
|
||||
memslot = gfn_to_memslot(kvm, gfn);
|
||||
|
||||
/* No memslot means it's an emulated MMIO region */
|
||||
if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
|
||||
if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS |
|
||||
DSISR_SET_RC)) {
|
||||
/*
|
||||
* Bad address in guest page table tree, or other
|
||||
* unusual error - reflect it to the guest as DSI.
|
||||
*/
|
||||
kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
|
||||
return RESUME_GUEST;
|
||||
}
|
||||
return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, writing);
|
||||
}
|
||||
|
||||
if (memslot->flags & KVM_MEM_READONLY) {
|
||||
if (writing) {
|
||||
/* give the guest a DSI */
|
||||
kvmppc_core_queue_data_storage(vcpu, ea, DSISR_ISSTORE |
|
||||
DSISR_PROTFAULT);
|
||||
return RESUME_GUEST;
|
||||
}
|
||||
kvm_ro = true;
|
||||
}
|
||||
|
||||
/* Failed to set the reference/change bits */
|
||||
if (dsisr & DSISR_SET_RC) {
|
||||
spin_lock(&kvm->mmu_lock);
|
||||
if (kvmppc_hv_handle_set_rc(kvm, kvm->arch.pgtable,
|
||||
writing, gpa))
|
||||
dsisr &= ~DSISR_SET_RC;
|
||||
spin_unlock(&kvm->mmu_lock);
|
||||
|
||||
if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
|
||||
DSISR_PROTFAULT | DSISR_SET_RC)))
|
||||
return RESUME_GUEST;
|
||||
}
|
||||
|
||||
/* Try to insert a pte */
|
||||
ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, writing,
|
||||
kvm_ro, NULL, NULL);
|
||||
|
||||
if (ret == 0 || ret == -EAGAIN)
|
||||
ret = RESUME_GUEST;
|
||||
return ret;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user