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authorSanjay Lal <sanjayl@kymasys.com>2013-05-18 17:54:24 +0400
committerGleb Natapov <gleb@redhat.com>2013-05-22 12:44:09 +0400
commit6d17c0d1e8a66f5508082cb0fecb8afb7e9a21e4 (patch)
treeeca5c93989a96bd5afff0e48178286861f8ce475 /arch
parentba86e4dda700b3e696119c7f4fad945b90cf5c84 (diff)
downloadlinux-6d17c0d1e8a66f5508082cb0fecb8afb7e9a21e4.tar.xz
KVM/MIPS32: Wrap calls to gfn_to_pfn() with srcu_read_lock/unlock()
- As suggested by Gleb, wrap calls to gfn_to_pfn() with srcu_read_lock/unlock(). Memory slots should be acccessed from a SRCU read section. - kvm_mips_map_page() now returns an error code to it's callers, instead of calling panic() if it cannot find a mapping for a particular gfn. Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/kvm/kvm_tlb.c35
1 files changed, 26 insertions, 9 deletions
diff --git a/arch/mips/kvm/kvm_tlb.c b/arch/mips/kvm/kvm_tlb.c
index 89511a9258d3..87d845e9e5ab 100644
--- a/arch/mips/kvm/kvm_tlb.c
+++ b/arch/mips/kvm/kvm_tlb.c
@@ -17,6 +17,8 @@
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/kvm_host.h>
+#include <linux/srcu.h>
+
#include <asm/cpu.h>
#include <asm/bootinfo.h>
@@ -169,21 +171,27 @@ void kvm_mips_dump_shadow_tlbs(struct kvm_vcpu *vcpu)
}
}
-static void kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
+static int kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
{
+ int srcu_idx, err = 0;
pfn_t pfn;
if (kvm->arch.guest_pmap[gfn] != KVM_INVALID_PAGE)
- return;
+ return 0;
+ srcu_idx = srcu_read_lock(&kvm->srcu);
pfn = kvm_mips_gfn_to_pfn(kvm, gfn);
if (kvm_mips_is_error_pfn(pfn)) {
- panic("Couldn't get pfn for gfn %#" PRIx64 "!\n", gfn);
+ kvm_err("Couldn't get pfn for gfn %#" PRIx64 "!\n", gfn);
+ err = -EFAULT;
+ goto out;
}
kvm->arch.guest_pmap[gfn] = pfn;
- return;
+out:
+ srcu_read_unlock(&kvm->srcu, srcu_idx);
+ return err;
}
/* Translate guest KSEG0 addresses to Host PA */
@@ -207,7 +215,10 @@ unsigned long kvm_mips_translate_guest_kseg0_to_hpa(struct kvm_vcpu *vcpu,
gva);
return KVM_INVALID_PAGE;
}
- kvm_mips_map_page(vcpu->kvm, gfn);
+
+ if (kvm_mips_map_page(vcpu->kvm, gfn) < 0)
+ return KVM_INVALID_ADDR;
+
return (kvm->arch.guest_pmap[gfn] << PAGE_SHIFT) + offset;
}
@@ -310,8 +321,11 @@ int kvm_mips_handle_kseg0_tlb_fault(unsigned long badvaddr,
even = !(gfn & 0x1);
vaddr = badvaddr & (PAGE_MASK << 1);
- kvm_mips_map_page(vcpu->kvm, gfn);
- kvm_mips_map_page(vcpu->kvm, gfn ^ 0x1);
+ if (kvm_mips_map_page(vcpu->kvm, gfn) < 0)
+ return -1;
+
+ if (kvm_mips_map_page(vcpu->kvm, gfn ^ 0x1) < 0)
+ return -1;
if (even) {
pfn0 = kvm->arch.guest_pmap[gfn];
@@ -389,8 +403,11 @@ kvm_mips_handle_mapped_seg_tlb_fault(struct kvm_vcpu *vcpu,
pfn0 = 0;
pfn1 = 0;
} else {
- kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo0) >> PAGE_SHIFT);
- kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo1) >> PAGE_SHIFT);
+ if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo0) >> PAGE_SHIFT) < 0)
+ return -1;
+
+ if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb->tlb_lo1) >> PAGE_SHIFT) < 0)
+ return -1;
pfn0 = kvm->arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb->tlb_lo0) >> PAGE_SHIFT];
pfn1 = kvm->arch.guest_pmap[mips3_tlbpfn_to_paddr(tlb->tlb_lo1) >> PAGE_SHIFT];