[PATCH v2 23/33] KVM: PPC: Book3S HV: Handle page fault for a nested guest
Paul Mackerras
paulus at ozlabs.org
Fri Sep 28 19:45:53 AEST 2018
From: Suraj Jitindar Singh <sjitindarsingh at gmail.com>
Consider a normal (L1) guest running under the main hypervisor (L0),
and then a nested guest (L2) running under the L1 guest which is acting
as a nested hypervisor. L0 has page tables to map the address space for
L1 providing the translation from L1 real address -> L0 real address;
L1
|
| (L1 -> L0)
|
----> L0
There are also page tables in L1 used to map the address space for L2
providing the translation from L2 real address -> L1 read address. Since
the hardware can only walk a single level of page table, we need to
maintain in L0 a "shadow_pgtable" for L2 which provides the translation
from L2 real address -> L0 real address. Which looks like;
L2 L2
| |
| (L2 -> L1) |
| |
----> L1 | (L2 -> L0)
| |
| (L1 -> L0) |
| |
----> L0 --------> L0
When a page fault occurs while running a nested (L2) guest we need to
insert a pte into this "shadow_pgtable" for the L2 -> L0 mapping. To
do this we need to:
1. Walk the pgtable in L1 memory to find the L2 -> L1 mapping, and
provide a page fault to L1 if this mapping doesn't exist.
2. Use our L1 -> L0 pgtable to convert this L1 address to an L0 address,
or try to insert a pte for that mapping if it doesn't exist.
3. Now we have a L2 -> L0 mapping, insert this into our shadow_pgtable
Once this mapping exists we can take rc faults when hardware is unable
to automatically set the reference and change bits in the pte. On these
we need to:
1. Check the rc bits on the L2 -> L1 pte match, and otherwise reflect
the fault down to L1.
2. Set the rc bits in the L1 -> L0 pte which corresponds to the same
host page.
3. Set the rc bits in the L2 -> L0 pte.
As we reuse a large number of functions in book3s_64_mmu_radix.c for
this we also needed to refactor a number of these functions to take
an lpid parameter so that the correct lpid is used for tlb invalidations.
The functionality however has remained the same.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh at gmail.com>
Signed-off-by: Paul Mackerras <paulus at ozlabs.org>
---
.../powerpc/include/asm/book3s/64/tlbflush-radix.h | 1 +
arch/powerpc/include/asm/kvm_book3s.h | 19 ++
arch/powerpc/include/asm/kvm_book3s_64.h | 4 +
arch/powerpc/include/asm/kvm_host.h | 2 +
arch/powerpc/kvm/book3s_64_mmu_radix.c | 196 +++++++-----
arch/powerpc/kvm/book3s_hv_nested.c | 333 ++++++++++++++++++++-
arch/powerpc/mm/tlb-radix.c | 9 +
7 files changed, 477 insertions(+), 87 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
index 1154a6d..671316f 100644
--- a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
+++ b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
@@ -53,6 +53,7 @@ extern void radix__flush_tlb_lpid_page(unsigned int lpid,
unsigned long addr,
unsigned long page_size);
extern void radix__flush_pwc_lpid(unsigned int lpid);
+extern void radix__flush_tlb_lpid(unsigned int lpid);
extern void radix__local_flush_tlb_lpid(unsigned int lpid);
extern void radix__local_flush_tlb_lpid_guest(unsigned int lpid);
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 80b43ac..045ab15 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -188,17 +188,34 @@ extern int kvmppc_book3s_hcall_implemented(struct kvm *kvm, unsigned long hc);
extern int kvmppc_book3s_radix_page_fault(struct kvm_run *run,
struct kvm_vcpu *vcpu,
unsigned long ea, unsigned long dsisr);
+extern int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr,
+ struct kvmppc_pte *gpte, u64 root,
+ u64 *pte_ret_p);
extern int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
struct kvmppc_pte *gpte, u64 table,
int table_index, u64 *pte_ret_p);
extern int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
struct kvmppc_pte *gpte, bool data, bool iswrite);
+extern bool kvmppc_hv_handle_set_rc(struct kvm *kvm, pgd_t *pgtable,
+ bool writing, unsigned long gpa,
+ unsigned int lpid);
+extern 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);
extern int kvmppc_init_vm_radix(struct kvm *kvm);
extern void kvmppc_free_radix(struct kvm *kvm);
+extern void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd,
+ unsigned int lpid);
extern int kvmppc_radix_init(void);
extern void kvmppc_radix_exit(void);
extern int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
unsigned long gfn);
+extern void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte,
+ unsigned long gpa, unsigned int shift,
+ struct kvm_memory_slot *memslot,
+ unsigned int lpid);
extern int kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
unsigned long gfn);
extern int kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
@@ -289,6 +306,8 @@ void kvmhv_restore_hv_return_state(struct kvm_vcpu *vcpu,
long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu);
int kvmhv_emulate_priv(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int instr);
+int kvmhv_handle_nested_trap(struct kvm_run *run, struct kvm_vcpu *vcpu,
+ struct task_struct *tsk);
void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac);
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 6d67b6a..5496152 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -549,6 +549,10 @@ static inline void copy_to_checkpoint(struct kvm_vcpu *vcpu)
}
#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+extern int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
+ unsigned long gpa, unsigned int level,
+ unsigned long mmu_seq, unsigned int lpid);
+
#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
#endif /* __ASM_KVM_BOOK3S_64_H__ */
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index ceb9f20..64c4807 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -367,7 +367,9 @@ struct kvmppc_pte {
bool may_write : 1;
bool may_execute : 1;
unsigned long wimg;
+ unsigned long rc;
u8 page_size; /* MMU_PAGE_xxx */
+ u16 page_shift;
};
struct kvmppc_mmu {
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index bd06a95..ee6f493 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -29,43 +29,16 @@
*/
static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 };
-/*
- * Used to walk a partition or process table radix tree in guest memory
- * Note: We exploit the fact that a partition table and a process
- * table have the same layout, a partition-scoped page table and a
- * process-scoped page table have the same layout, and the 2nd
- * doubleword of a partition table entry has the same layout as
- * the PTCR register.
- */
-int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
- struct kvmppc_pte *gpte, u64 table,
- int table_index, u64 *pte_ret_p)
+int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr,
+ struct kvmppc_pte *gpte, u64 root,
+ u64 *pte_ret_p)
{
struct kvm *kvm = vcpu->kvm;
int ret, level, ps;
- unsigned long ptbl, root;
- unsigned long rts, bits, offset;
- unsigned long size, index;
- struct prtb_entry entry;
+ unsigned long rts, bits, offset, index;
u64 pte, base, gpa;
__be64 rpte;
- if ((table & PRTS_MASK) > 24)
- return -EINVAL;
- size = 1ul << ((table & PRTS_MASK) + 12);
-
- /* Is the table big enough to contain this entry? */
- if ((table_index * sizeof(entry)) >= size)
- return -EINVAL;
-
- /* Read the table to find the root of the radix tree */
- ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry));
- ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry));
- if (ret)
- return ret;
-
- /* Root is stored in the first double word */
- root = be64_to_cpu(entry.prtb0);
rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) |
((root & RTS2_MASK) >> RTS2_SHIFT);
bits = root & RPDS_MASK;
@@ -79,6 +52,7 @@ int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
/* Walk each level of the radix tree */
for (level = 3; level >= 0; --level) {
+ u64 addr;
/* Check a valid size */
if (level && bits != p9_supported_radix_bits[level])
return -EINVAL;
@@ -90,10 +64,13 @@ int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
if (base & ((1UL << (bits + 3)) - 1))
return -EINVAL;
/* Read the entry from guest memory */
- ret = kvm_read_guest(kvm, base + (index * sizeof(rpte)),
- &rpte, sizeof(rpte));
- if (ret)
+ addr = base + (index * sizeof(rpte));
+ ret = kvm_read_guest(kvm, addr, &rpte, sizeof(rpte));
+ if (ret) {
+ if (pte_ret_p)
+ *pte_ret_p = addr;
return ret;
+ }
pte = __be64_to_cpu(rpte);
if (!(pte & _PAGE_PRESENT))
return -ENOENT;
@@ -119,6 +96,7 @@ int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
if (offset == mmu_psize_defs[ps].shift)
break;
gpte->page_size = ps;
+ gpte->page_shift = offset;
gpte->eaddr = eaddr;
gpte->raddr = gpa;
@@ -128,12 +106,51 @@ int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
gpte->may_write = !!(pte & _PAGE_WRITE);
gpte->may_execute = !!(pte & _PAGE_EXEC);
+ gpte->rc = pte & (_PAGE_ACCESSED | _PAGE_DIRTY);
+
if (pte_ret_p)
*pte_ret_p = pte;
return 0;
}
+/*
+ * Used to walk a partition or process table radix tree in guest memory
+ * Note: We exploit the fact that a partition table and a process
+ * table have the same layout, a partition-scoped page table and a
+ * process-scoped page table have the same layout, and the 2nd
+ * doubleword of a partition table entry has the same layout as
+ * the PTCR register.
+ */
+int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr,
+ struct kvmppc_pte *gpte, u64 table,
+ int table_index, u64 *pte_ret_p)
+{
+ struct kvm *kvm = vcpu->kvm;
+ int ret;
+ unsigned long size, ptbl, root;
+ struct prtb_entry entry;
+
+ if ((table & PRTS_MASK) > 24)
+ return -EINVAL;
+ size = 1ul << ((table & PRTS_MASK) + 12);
+
+ /* Is the table big enough to contain this entry? */
+ if ((table_index * sizeof(entry)) >= size)
+ return -EINVAL;
+
+ /* Read the table to find the root of the radix tree */
+ ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry));
+ ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry));
+ if (ret)
+ return ret;
+
+ /* Root is stored in the first double word */
+ root = be64_to_cpu(entry.prtb0);
+
+ return kvmppc_mmu_walk_radix_tree(vcpu, eaddr, gpte, root, pte_ret_p);
+}
+
int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
struct kvmppc_pte *gpte, bool data, bool iswrite)
{
@@ -181,7 +198,7 @@ int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
}
static void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
- unsigned int pshift)
+ unsigned int pshift, unsigned int lpid)
{
unsigned long psize = PAGE_SIZE;
@@ -189,12 +206,12 @@ static void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
psize = 1UL << pshift;
addr &= ~(psize - 1);
- radix__flush_tlb_lpid_page(kvm->arch.lpid, addr, psize);
+ radix__flush_tlb_lpid_page(lpid, addr, psize);
}
-static void kvmppc_radix_flush_pwc(struct kvm *kvm)
+static void kvmppc_radix_flush_pwc(struct kvm *kvm, unsigned int lpid)
{
- radix__flush_pwc_lpid(kvm->arch.lpid);
+ radix__flush_pwc_lpid(lpid);
}
static unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep,
@@ -239,16 +256,17 @@ static void kvmppc_pmd_free(pmd_t *pmdp)
kmem_cache_free(kvm_pmd_cache, pmdp);
}
-static void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte,
- unsigned long gpa, unsigned int shift,
- struct kvm_memory_slot *memslot)
+void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte,
+ unsigned long gpa, unsigned int shift,
+ struct kvm_memory_slot *memslot,
+ unsigned int lpid)
{
unsigned long old;
old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift);
- kvmppc_radix_tlbie_page(kvm, gpa, shift);
- if (old & _PAGE_DIRTY) {
+ kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
+ if ((old & _PAGE_DIRTY) && (lpid == kvm->arch.lpid)) {
unsigned long gfn = gpa >> PAGE_SHIFT;
unsigned long page_size = PAGE_SIZE;
@@ -271,7 +289,8 @@ static void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte,
* and emit a warning if encountered, but there may already be data
* corruption due to the unexpected mappings.
*/
-static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full)
+static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full,
+ unsigned int lpid)
{
if (full) {
memset(pte, 0, sizeof(long) << PTE_INDEX_SIZE);
@@ -285,14 +304,15 @@ static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full)
WARN_ON_ONCE(1);
kvmppc_unmap_pte(kvm, p,
pte_pfn(*p) << PAGE_SHIFT,
- PAGE_SHIFT, NULL);
+ PAGE_SHIFT, NULL, lpid);
}
}
kvmppc_pte_free(pte);
}
-static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full)
+static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full,
+ unsigned int lpid)
{
unsigned long im;
pmd_t *p = pmd;
@@ -307,20 +327,21 @@ static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full)
WARN_ON_ONCE(1);
kvmppc_unmap_pte(kvm, (pte_t *)p,
pte_pfn(*(pte_t *)p) << PAGE_SHIFT,
- PMD_SHIFT, NULL);
+ PMD_SHIFT, NULL, lpid);
}
} else {
pte_t *pte;
pte = pte_offset_map(p, 0);
- kvmppc_unmap_free_pte(kvm, pte, full);
+ kvmppc_unmap_free_pte(kvm, pte, full, lpid);
pmd_clear(p);
}
}
kvmppc_pmd_free(pmd);
}
-static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud)
+static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud,
+ unsigned int lpid)
{
unsigned long iu;
pud_t *p = pud;
@@ -334,36 +355,42 @@ static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud)
pmd_t *pmd;
pmd = pmd_offset(p, 0);
- kvmppc_unmap_free_pmd(kvm, pmd, true);
+ kvmppc_unmap_free_pmd(kvm, pmd, true, lpid);
pud_clear(p);
}
}
pud_free(kvm->mm, pud);
}
-void kvmppc_free_radix(struct kvm *kvm)
+void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd, unsigned int lpid)
{
unsigned long ig;
- pgd_t *pgd;
- if (!kvm->arch.pgtable)
+ if (!pgd)
return;
- pgd = kvm->arch.pgtable;
for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
pud_t *pud;
if (!pgd_present(*pgd))
continue;
pud = pud_offset(pgd, 0);
- kvmppc_unmap_free_pud(kvm, pud);
+ kvmppc_unmap_free_pud(kvm, pud, lpid);
pgd_clear(pgd);
}
- pgd_free(kvm->mm, kvm->arch.pgtable);
- kvm->arch.pgtable = NULL;
+}
+
+void kvmppc_free_radix(struct kvm *kvm)
+{
+ if (kvm->arch.pgtable) {
+ kvmppc_free_pgtable_radix(kvm, kvm->arch.pgtable,
+ kvm->arch.lpid);
+ pgd_free(kvm->mm, kvm->arch.pgtable);
+ kvm->arch.pgtable = NULL;
+ }
}
static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd,
- unsigned long gpa)
+ unsigned long gpa, unsigned int lpid)
{
pte_t *pte = pte_offset_kernel(pmd, 0);
@@ -373,13 +400,13 @@ static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd,
* flushing the PWC again.
*/
pmd_clear(pmd);
- kvmppc_radix_flush_pwc(kvm);
+ kvmppc_radix_flush_pwc(kvm, lpid);
- kvmppc_unmap_free_pte(kvm, pte, false);
+ kvmppc_unmap_free_pte(kvm, pte, false, lpid);
}
static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud,
- unsigned long gpa)
+ unsigned long gpa, unsigned int lpid)
{
pmd_t *pmd = pmd_offset(pud, 0);
@@ -389,9 +416,9 @@ static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud,
* so can be freed without flushing the PWC again.
*/
pud_clear(pud);
- kvmppc_radix_flush_pwc(kvm);
+ kvmppc_radix_flush_pwc(kvm, lpid);
- kvmppc_unmap_free_pmd(kvm, pmd, false);
+ kvmppc_unmap_free_pmd(kvm, pmd, false, lpid);
}
/*
@@ -403,9 +430,9 @@ 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, pgd_t *pgtable, pte_t pte,
- unsigned long gpa, unsigned int level,
- unsigned long mmu_seq)
+int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
+ unsigned long gpa, unsigned int level,
+ unsigned long mmu_seq, unsigned int lpid)
{
pgd_t *pgd;
pud_t *pud, *new_pud = NULL;
@@ -458,7 +485,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
WARN_ON_ONCE((pud_val(*pud) ^ pte_val(pte)) &
PTE_BITS_MUST_MATCH);
kvmppc_radix_update_pte(kvm, (pte_t *)pud,
- 0, pte_val(pte), hgpa, PUD_SHIFT);
+ 0, pte_val(pte), hgpa, PUD_SHIFT);
ret = 0;
goto out_unlock;
}
@@ -471,7 +498,8 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
goto out_unlock;
}
/* Valid 1GB page here already, remove it */
- kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL);
+ kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL,
+ lpid);
}
if (level == 2) {
if (!pud_none(*pud)) {
@@ -480,7 +508,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
* install a large page, so remove and free the page
* table page.
*/
- kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa);
+ kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa, lpid);
}
kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte);
ret = 0;
@@ -506,7 +534,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
WARN_ON_ONCE((pmd_val(*pmd) ^ pte_val(pte)) &
PTE_BITS_MUST_MATCH);
kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd),
- 0, pte_val(pte), lgpa, PMD_SHIFT);
+ 0, pte_val(pte), lgpa, PMD_SHIFT);
ret = 0;
goto out_unlock;
}
@@ -520,7 +548,8 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
goto out_unlock;
}
/* Valid 2MB page here already, remove it */
- kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL);
+ kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL,
+ lpid);
}
if (level == 1) {
if (!pmd_none(*pmd)) {
@@ -529,7 +558,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
* install a large page, so remove and free the page
* table page.
*/
- kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa);
+ kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa, lpid);
}
kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte);
ret = 0;
@@ -569,8 +598,8 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
return ret;
}
-static bool kvmppc_hv_handle_set_rc(struct kvm *kvm, pgd_t *pgtable,
- bool writing, unsigned long gpa)
+bool kvmppc_hv_handle_set_rc(struct kvm *kvm, pgd_t *pgtable, bool writing,
+ unsigned long gpa, unsigned int lpid)
{
unsigned long pgflags;
unsigned int shift;
@@ -597,11 +626,11 @@ static bool kvmppc_hv_handle_set_rc(struct kvm *kvm, pgd_t *pgtable,
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)
+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;
struct page *page = NULL;
@@ -683,7 +712,7 @@ static int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu,
/* Allocate space in the tree and write the PTE */
ret = kvmppc_create_pte(kvm, kvm->arch.pgtable, pte, gpa, level,
- mmu_seq);
+ mmu_seq, kvm->arch.lpid);
if (inserted_pte)
*inserted_pte = pte;
if (levelp)
@@ -758,7 +787,7 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
if (dsisr & DSISR_SET_RC) {
spin_lock(&kvm->mmu_lock);
if (kvmppc_hv_handle_set_rc(kvm, kvm->arch.pgtable,
- writing, gpa))
+ writing, gpa, kvm->arch.lpid))
dsisr &= ~DSISR_SET_RC;
spin_unlock(&kvm->mmu_lock);
@@ -786,7 +815,8 @@ int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
if (ptep && pte_present(*ptep))
- kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot);
+ kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
+ kvm->arch.lpid);
return 0;
}
@@ -841,7 +871,7 @@ static int kvm_radix_test_clear_dirty(struct kvm *kvm,
ret = 1 << (shift - PAGE_SHIFT);
kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0,
gpa, shift);
- kvmppc_radix_tlbie_page(kvm, gpa, shift);
+ kvmppc_radix_tlbie_page(kvm, gpa, shift, kvm->arch.lpid);
}
return ret;
}
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index b004639..b1bfa6b 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -12,10 +12,13 @@
#include <linux/kvm_host.h>
#include <asm/kvm_ppc.h>
+#include <asm/kvm_book3s.h>
#include <asm/mmu.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
+#include <asm/pte-walk.h>
#include <asm/disassemble.h>
+#include <asm/reg.h>
static struct patb_entry *pseries_partition_tb;
@@ -389,10 +392,20 @@ struct kvm_nested_guest *kvmhv_alloc_nested(struct kvm *kvm, unsigned int lpid)
*/
static void kvmhv_release_nested(struct kvm_nested_guest *gp)
{
+ struct kvm *kvm = gp->l1_host;
+
kvmhv_set_ptbl_entry(gp->shadow_lpid, 0, 0);
+ if (gp->shadow_pgtable) {
+ /*
+ * No vcpu is using this struct and no call to
+ * kvmhv_remove_nest_rmap can find this struct,
+ * so we don't need to hold kvm->mmu_lock.
+ */
+ kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable,
+ gp->shadow_lpid);
+ pgd_free(kvm->mm, gp->shadow_pgtable);
+ }
kvmppc_free_lpid(gp->shadow_lpid);
- if (gp->shadow_pgtable)
- pgd_free(gp->l1_host->mm, gp->shadow_pgtable);
kfree(gp);
}
@@ -449,6 +462,11 @@ void kvmhv_release_all_nested(struct kvm *kvm)
/* caller must hold gp->tlb_lock */
void kvmhv_flush_nested(struct kvm_nested_guest *gp)
{
+ struct kvm *kvm = gp->l1_host;
+
+ spin_lock(&kvm->mmu_lock);
+ kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, gp->shadow_lpid);
+ spin_unlock(&kvm->mmu_lock);
kvmhv_update_ptbl_cache(gp);
if (gp->l1_gr_to_hr == 0)
kvmhv_remove_nested(gp);
@@ -508,9 +526,28 @@ void kvmhv_put_nested(struct kvm_nested_guest *gp)
kvmhv_release_nested(gp);
}
-long kvmhv_nested_page_fault(struct kvm_vcpu *vcpu)
+static bool kvmhv_invalidate_shadow_pte(struct kvm_vcpu *vcpu,
+ struct kvm_nested_guest *gp,
+ long gpa, int *shift_ret)
{
- return RESUME_HOST;
+ struct kvm *kvm = vcpu->kvm;
+ bool ret = false;
+ pte_t *ptep;
+ int shift;
+
+ spin_lock(&kvm->mmu_lock);
+ ptep = __find_linux_pte(gp->shadow_pgtable, gpa, NULL, &shift);
+ if (!shift)
+ shift = PAGE_SHIFT;
+ if (ptep && pte_present(*ptep)) {
+ kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
+ ret = true;
+ }
+ spin_unlock(&kvm->mmu_lock);
+
+ if (shift_ret)
+ *shift_ret = shift;
+ return ret;
}
static int kvmhv_emulate_priv_mtspr(struct kvm_run *run, struct kvm_vcpu *vcpu,
@@ -566,3 +603,291 @@ int kvmhv_emulate_priv(struct kvm_run *run, struct kvm_vcpu *vcpu,
return rc;
}
+
+/* Used to convert a nested guest real address to a L1 guest real address */
+static int kvmhv_translate_addr_nested(struct kvm_vcpu *vcpu,
+ struct kvm_nested_guest *gp,
+ unsigned long n_gpa, unsigned long dsisr,
+ struct kvmppc_pte *gpte_p)
+{
+ u64 fault_addr, flags = dsisr & DSISR_ISSTORE;
+ int ret;
+
+ ret = kvmppc_mmu_walk_radix_tree(vcpu, n_gpa, gpte_p, gp->l1_gr_to_hr,
+ &fault_addr);
+
+ if (ret) {
+ /* We didn't find a pte */
+ if (ret == -EINVAL) {
+ /* Unsupported mmu config */
+ flags |= DSISR_UNSUPP_MMU;
+ } else if (ret == -ENOENT) {
+ /* No translation found */
+ flags |= DSISR_NOHPTE;
+ } else if (ret == -EFAULT) {
+ /* Couldn't access L1 real address */
+ flags |= DSISR_PRTABLE_FAULT;
+ vcpu->arch.fault_gpa = fault_addr;
+ } else {
+ /* Unknown error */
+ return ret;
+ }
+ goto resume_host;
+ } else {
+ /* We found a pte -> check permissions */
+ if (dsisr & DSISR_ISSTORE) {
+ /* Can we write? */
+ if (!gpte_p->may_write) {
+ flags |= DSISR_PROTFAULT;
+ goto resume_host;
+ }
+ } else if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
+ /* Can we execute? */
+ if (!gpte_p->may_execute) {
+ flags |= SRR1_ISI_N_OR_G;
+ goto resume_host;
+ }
+ } else {
+ /* Can we read? */
+ if (!gpte_p->may_read && !gpte_p->may_write) {
+ flags |= DSISR_PROTFAULT;
+ goto resume_host;
+ }
+ }
+ }
+
+ return 0;
+
+resume_host:
+ vcpu->arch.fault_dsisr = flags;
+ if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
+ vcpu->arch.shregs.msr &= ~0x783f0000ul;
+ vcpu->arch.shregs.msr |= flags;
+ }
+ return RESUME_HOST;
+}
+
+static long kvmhv_handle_nested_set_rc(struct kvm_vcpu *vcpu,
+ struct kvm_nested_guest *gp,
+ unsigned long n_gpa,
+ struct kvmppc_pte gpte,
+ unsigned long dsisr)
+{
+ struct kvm *kvm = vcpu->kvm;
+ bool writing = !!(dsisr & DSISR_ISSTORE);
+ u64 pgflags;
+ bool ret;
+
+ /* Are the rc bits set in the L1 partition scoped pte? */
+ pgflags = _PAGE_ACCESSED;
+ if (writing)
+ pgflags |= _PAGE_DIRTY;
+ if (pgflags & ~gpte.rc)
+ return RESUME_HOST;
+
+ spin_lock(&kvm->mmu_lock);
+ /* Set the rc bit in the pte of our (L0) pgtable for the L1 guest */
+ ret = kvmppc_hv_handle_set_rc(kvm, kvm->arch.pgtable, writing,
+ gpte.raddr, kvm->arch.lpid);
+ spin_unlock(&kvm->mmu_lock);
+ if (!ret)
+ return -EINVAL;
+
+ /* Set the rc bit in the pte of the shadow_pgtable for the nest guest */
+ ret = kvmppc_hv_handle_set_rc(kvm, gp->shadow_pgtable, writing, n_gpa,
+ gp->shadow_lpid);
+ if (!ret)
+ return -EINVAL;
+ return 0;
+}
+
+static inline int kvmppc_radix_level_to_shift(int level)
+{
+ switch (level) {
+ case 2:
+ return PUD_SHIFT;
+ case 1:
+ return PMD_SHIFT;
+ default:
+ return PAGE_SHIFT;
+ }
+}
+
+static inline int kvmppc_radix_shift_to_level(int shift)
+{
+ if (shift == PUD_SHIFT)
+ return 2;
+ if (shift == PMD_SHIFT)
+ return 1;
+ if (shift == PAGE_SHIFT)
+ return 0;
+ WARN_ON_ONCE(1);
+ return 0;
+}
+
+/* called with gp->tlb_lock held */
+static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu,
+ struct kvm_nested_guest *gp)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct kvm_memory_slot *memslot;
+ struct kvmppc_pte gpte;
+ pte_t pte, *pte_p;
+ unsigned long mmu_seq;
+ unsigned long dsisr = vcpu->arch.fault_dsisr;
+ unsigned long ea = vcpu->arch.fault_dar;
+ unsigned long n_gpa, gpa, gfn, perm = 0UL;
+ unsigned int shift, l1_shift, level;
+ bool writing = !!(dsisr & DSISR_ISSTORE);
+ bool kvm_ro = false;
+ long int ret;
+
+ if (!gp->l1_gr_to_hr) {
+ kvmhv_update_ptbl_cache(gp);
+ if (!gp->l1_gr_to_hr)
+ return RESUME_HOST;
+ }
+
+ /* Convert the nested guest real address into a L1 guest real address */
+
+ n_gpa = vcpu->arch.fault_gpa & ~0xF000000000000FFFULL;
+ if (!(dsisr & DSISR_PRTABLE_FAULT))
+ n_gpa |= ea & 0xFFF;
+ ret = kvmhv_translate_addr_nested(vcpu, gp, n_gpa, dsisr, &gpte);
+
+ /*
+ * If the hardware found a translation but we don't now have a usable
+ * translation in the l1 partition-scoped tree, remove the shadow pte
+ * and let the guest retry.
+ */
+ if (ret == RESUME_HOST &&
+ (dsisr & (DSISR_PROTFAULT | DSISR_BADACCESS | DSISR_NOEXEC_OR_G |
+ DSISR_BAD_COPYPASTE)))
+ goto inval;
+ if (ret)
+ return ret;
+
+ /* Failed to set the reference/change bits */
+ if (dsisr & DSISR_SET_RC) {
+ ret = kvmhv_handle_nested_set_rc(vcpu, gp, n_gpa, gpte, dsisr);
+ if (ret == RESUME_HOST)
+ return ret;
+ if (ret)
+ goto inval;
+ dsisr &= ~DSISR_SET_RC;
+ if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
+ DSISR_PROTFAULT)))
+ return RESUME_GUEST;
+ }
+
+ /*
+ * We took an HISI or HDSI while we were running a nested guest which
+ * means we have no partition scoped translation for that. This means
+ * we need to insert a pte for the mapping into our shadow_pgtable.
+ */
+
+ l1_shift = gpte.page_shift;
+ if (l1_shift < PAGE_SHIFT) {
+ /* We don't support l1 using a page size smaller than our own */
+ pr_err("KVM: L1 guest page shift (%d) less than our own (%d)\n",
+ l1_shift, PAGE_SHIFT);
+ return -EINVAL;
+ }
+ gpa = gpte.raddr;
+ gfn = gpa >> PAGE_SHIFT;
+
+ /* 1. Get the corresponding host memslot */
+
+ memslot = gfn_to_memslot(kvm, gfn);
+ if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
+ if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS)) {
+ /* unusual error -> reflect to the guest as a DSI */
+ kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
+ return RESUME_GUEST;
+ }
+ /* passthrough of emulated MMIO case... */
+ pr_err("emulated MMIO passthrough?\n");
+ return -EINVAL;
+ }
+ 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;
+ }
+
+ /* 2. Find the host pte for this L1 guest real address */
+
+ /* Used to check for invalidations in progress */
+ mmu_seq = kvm->mmu_notifier_seq;
+ smp_rmb();
+
+ /* See if can find translation in our partition scoped tables for L1 */
+ pte = __pte(0);
+ spin_lock(&kvm->mmu_lock);
+ pte_p = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
+ if (!shift)
+ shift = PAGE_SHIFT;
+ if (pte_p)
+ pte = *pte_p;
+ spin_unlock(&kvm->mmu_lock);
+
+ if (!pte_present(pte) || (writing && !(pte_val(pte) & _PAGE_WRITE))) {
+ /* No suitable pte found -> try to insert a mapping */
+ ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot,
+ writing, kvm_ro, &pte, &level);
+ if (ret == -EAGAIN)
+ return RESUME_GUEST;
+ else if (ret)
+ return ret;
+ shift = kvmppc_radix_level_to_shift(level);
+ }
+
+ /* 3. Compute the pte we need to insert for nest_gpa -> host r_addr */
+
+ /* The permissions is the combination of the host and l1 guest ptes */
+ perm |= gpte.may_read ? 0UL : _PAGE_READ;
+ perm |= gpte.may_write ? 0UL : _PAGE_WRITE;
+ perm |= gpte.may_execute ? 0UL : _PAGE_EXEC;
+ pte = __pte(pte_val(pte) & ~perm);
+
+ /* What size pte can we insert? */
+ if (shift > l1_shift) {
+ u64 mask;
+ unsigned int actual_shift = PAGE_SHIFT;
+ if (PMD_SHIFT < l1_shift)
+ actual_shift = PMD_SHIFT;
+ mask = (1UL << shift) - (1UL << actual_shift);
+ pte = __pte(pte_val(pte) | (gpa & mask));
+ shift = actual_shift;
+ }
+ level = kvmppc_radix_shift_to_level(shift);
+ n_gpa &= ~((1UL << shift) - 1);
+
+ /* 4. Insert the pte into our shadow_pgtable */
+
+ ret = kvmppc_create_pte(kvm, gp->shadow_pgtable, pte, n_gpa, level,
+ mmu_seq, gp->shadow_lpid);
+ if (ret == -EAGAIN)
+ ret = RESUME_GUEST; /* Let the guest try again */
+
+ return ret;
+
+ inval:
+ kvmhv_invalidate_shadow_pte(vcpu, gp, n_gpa, NULL);
+ return RESUME_GUEST;
+}
+
+long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu)
+{
+ struct kvm_nested_guest *gp = vcpu->arch.nested;
+ long int ret;
+
+ mutex_lock(&gp->tlb_lock);
+ ret = __kvmhv_nested_page_fault(vcpu, gp);
+ mutex_unlock(&gp->tlb_lock);
+ return ret;
+}
diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c
index fef3e1e..4c4dfc4 100644
--- a/arch/powerpc/mm/tlb-radix.c
+++ b/arch/powerpc/mm/tlb-radix.c
@@ -833,6 +833,15 @@ EXPORT_SYMBOL_GPL(radix__flush_pwc_lpid);
/*
* Flush partition scoped translations from LPID (=LPIDR)
*/
+void radix__flush_tlb_lpid(unsigned int lpid)
+{
+ _tlbie_lpid(lpid, RIC_FLUSH_ALL);
+}
+EXPORT_SYMBOL_GPL(radix__flush_tlb_lpid);
+
+/*
+ * Flush partition scoped translations from LPID (=LPIDR)
+ */
void radix__local_flush_tlb_lpid(unsigned int lpid)
{
_tlbiel_lpid(lpid, RIC_FLUSH_ALL);
--
2.7.4
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