This provides for the case where userspace maps an I/O device into the
address range of a memory slot using a VM_PFNMAP mapping. In that
case, we work out the pfn from vma->vm_pgoff, and record the cache
enable bits from vma->vm_page_prot in two low-order bits in the
slot_phys array entries. Then, in kvmppc_h_enter() we check that the
cache bits in the HPTE that the guest wants to insert match the cache
bits in the slot_phys array entry.
Signed-off-by: Paul Mackerras <pau...@samba.org>
---
arch/powerpc/include/asm/kvm_book3s_64.h | 26 +++++++++++
arch/powerpc/include/asm/kvm_host.h | 2 +
arch/powerpc/kvm/book3s_64_mmu_hv.c | 67 ++++++++++++++++++++----------
arch/powerpc/kvm/book3s_hv_rm_mmu.c | 5 +-
4 files changed, 76 insertions(+), 24 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h
b/arch/powerpc/include/asm/kvm_book3s_64.h
index d55e6b4..a98e0f6 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -107,6 +107,32 @@ static inline unsigned long hpte_page_size(unsigned long
h, unsigned long l)
return 0; /* error */
}
+static inline int hpte_cache_flags_ok(unsigned long ptel, unsigned long
io_type)
+{
+ unsigned int wimg = ptel & HPTE_R_WIMG;
+
+ /* Handle SAO */
+ if (wimg == (HPTE_R_W | HPTE_R_I | HPTE_R_M) &&
+ cpu_has_feature(CPU_FTR_ARCH_206))
+ wimg = HPTE_R_M;
+
+ if (!io_type)
+ return wimg == HPTE_R_M;
+
+ return (wimg & (HPTE_R_W | HPTE_R_I)) == io_type;
+}
+
+/* Return HPTE cache control bits corresponding to Linux pte bits */
+static inline unsigned long hpte_cache_bits(unsigned long pte_val)
+{
+#if _PAGE_NO_CACHE == HPTE_R_I && _PAGE_WRITETHRU == HPTE_R_W
+ return pte_val & (HPTE_R_W | HPTE_R_I);
+#else
+ return ((pte_val & _PAGE_NO_CACHE) ? HPTE_R_I : 0) +
+ ((pte_val & _PAGE_WRITETHRU) ? HPTE_R_W : 0);
+#endif
+}
+
static inline bool slot_is_aligned(struct kvm_memory_slot *memslot,
unsigned long pagesize)
{
diff --git a/arch/powerpc/include/asm/kvm_host.h
b/arch/powerpc/include/asm/kvm_host.h
index ba1da85..9b1c247 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -177,6 +177,8 @@ struct revmap_entry {
/* Low-order bits in kvm->arch.slot_phys[][] */
#define KVMPPC_PAGE_ORDER_MASK 0x1f
+#define KVMPPC_PAGE_NO_CACHE HPTE_R_I /* 0x20 */
+#define KVMPPC_PAGE_WRITETHRU HPTE_R_W /* 0x40 */
#define KVMPPC_GOT_PAGE 0x80
struct kvm_arch {
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c
b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index cc18f3d..b904c40 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -199,7 +199,8 @@ static long kvmppc_get_guest_page(struct kvm *kvm, unsigned
long gfn,
struct page *page, *hpage, *pages[1];
unsigned long s, pgsize;
unsigned long *physp;
- unsigned int got, pgorder;
+ unsigned int is_io, got, pgorder;
+ struct vm_area_struct *vma;
unsigned long pfn, i, npages;
physp = kvm->arch.slot_phys[memslot->id];
@@ -208,34 +209,51 @@ static long kvmppc_get_guest_page(struct kvm *kvm,
unsigned long gfn,
if (physp[gfn - memslot->base_gfn])
return 0;
+ is_io = 0;
+ got = 0;
page = NULL;
pgsize = psize;
+ err = -EINVAL;
start = gfn_to_hva_memslot(memslot, gfn);
/* Instantiate and get the page we want access to */
np = get_user_pages_fast(start, 1, 1, pages);
- if (np != 1)
- return -EINVAL;
- page = pages[0];
- got = KVMPPC_GOT_PAGE;
+ if (np != 1) {
+ /* Look up the vma for the page */
+ down_read(¤t->mm->mmap_sem);
+ vma = find_vma(current->mm, start);
+ if (!vma || vma->vm_start > start ||
+ start + psize > vma->vm_end ||
+ !(vma->vm_flags & VM_PFNMAP))
+ goto up_err;
+ is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
+ pfn = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
+ /* check alignment of pfn vs. requested page size */
+ if (psize > PAGE_SIZE && (pfn & ((psize >> PAGE_SHIFT) - 1)))
+ goto up_err;
+ up_read(¤t->mm->mmap_sem);
- /* See if this is a large page */
- s = PAGE_SIZE;
- if (PageHuge(page)) {
- hpage = compound_head(page);
- s <<= compound_order(hpage);
- /* Get the whole large page if slot alignment is ok */
- if (s > psize && slot_is_aligned(memslot, s) &&
- !(memslot->userspace_addr & (s - 1))) {
- start &= ~(s - 1);
- pgsize = s;
- page = hpage;
+ } else {
+ page = pages[0];
+ got = KVMPPC_GOT_PAGE;
+
+ /* See if this is a large page */
+ s = PAGE_SIZE;
+ if (PageHuge(page)) {
+ hpage = compound_head(page);
+ s <<= compound_order(hpage);
+ /* Get the whole large page if slot alignment is ok */
+ if (s > psize && slot_is_aligned(memslot, s) &&
+ !(memslot->userspace_addr & (s - 1))) {
+ start &= ~(s - 1);
+ pgsize = s;
+ page = hpage;
+ }
}
+ if (s < psize)
+ goto out;
+ pfn = page_to_pfn(page);
}
- err = -EINVAL;
- if (s < psize)
- goto out;
- pfn = page_to_pfn(page);
npages = pgsize >> PAGE_SHIFT;
pgorder = __ilog2(npages);
@@ -243,7 +261,8 @@ static long kvmppc_get_guest_page(struct kvm *kvm, unsigned
long gfn,
spin_lock(&kvm->arch.slot_phys_lock);
for (i = 0; i < npages; ++i) {
if (!physp[i]) {
- physp[i] = ((pfn + i) << PAGE_SHIFT) + got + pgorder;
+ physp[i] = ((pfn + i) << PAGE_SHIFT) +
+ got + is_io + pgorder;
got = 0;
}
}
@@ -257,6 +276,10 @@ static long kvmppc_get_guest_page(struct kvm *kvm,
unsigned long gfn,
put_page(page);
}
return err;
+
+ up_err:
+ up_read(¤t->mm->mmap_sem);
+ return err;
}
/*
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index c76305c..88d2add 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -68,6 +68,7 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long
flags,
unsigned long g_ptel = ptel;
struct kvm_memory_slot *memslot;
unsigned long *physp, pte_size;
+ unsigned long is_io;
bool realmode = vcpu->arch.vcore->vcore_state == VCORE_RUNNING;
psize = hpte_page_size(pteh, ptel);
@@ -95,6 +96,7 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long
flags,
pa = *physp;
if (!pa)
return H_TOO_HARD;
+ is_io = pa & (HPTE_R_I | HPTE_R_W);
pte_size = PAGE_SIZE << (pa & KVMPPC_PAGE_ORDER_MASK);
pa &= PAGE_MASK;
@@ -107,8 +109,7 @@ long kvmppc_h_enter(struct kvm_vcpu *vcpu, unsigned long
flags,
ptel |= pa;
/* Check WIMG */
- if ((ptel & HPTE_R_WIMG) != HPTE_R_M &&
- (ptel & HPTE_R_WIMG) != (HPTE_R_W | HPTE_R_I | HPTE_R_M))
+ if (!hpte_cache_flags_ok(ptel, is_io))
return H_PARAMETER;
pteh &= ~0x60UL;
pteh |= HPTE_V_VALID;
--
1.7.5.4
--
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