On 08/22/2012 08:06 PM, Avi Kivity wrote: > On 08/21/2012 06:03 AM, Xiao Guangrong wrote: >> Introduce write_readonly_mem in mmio-exit-info to indicate this exit is >> caused by write access on readonly memslot > > Please document this in chapter 5 of apic.txt. >
Okay, please review this one. Subject: [PATCH v6 12/12] KVM: indicate readonly access fault Introduce write_readonly_mem in mmio-exit-info to indicate this exit is caused by write access on readonly memslot Signed-off-by: Xiao Guangrong <[email protected]> --- Documentation/virtual/kvm/api.txt | 8 +++++++- arch/x86/kvm/x86.c | 23 ++++++++++++++--------- include/linux/kvm.h | 3 +++ include/linux/kvm_host.h | 1 + virt/kvm/kvm_main.c | 3 +++ 5 files changed, 28 insertions(+), 10 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index b91bfd4..baf477e 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2089,12 +2089,18 @@ Unused. __u8 data[8]; __u32 len; __u8 is_write; +#ifdef __KVM_HAVE_READONLY_MEM + __u8 write_readonly_mem; +#endif } mmio; If exit_reason is KVM_EXIT_MMIO, then the vcpu has executed a memory-mapped I/O instruction which could not be satisfied by kvm. The 'data' member contains the written data if 'is_write' is -true, and should be filled by application code otherwise. +true, and should be filled by application code otherwise. When the +KVM_CAP_READONLY_MEM capability, the 'write_readonly_mem' member indicates +whether the exit is caused by write access on the readonly memslot +(see KVM_MEM_READONLY in 4.35 KVM_SET_USER_MEMORY_REGION). NOTE: For KVM_EXIT_IO, KVM_EXIT_MMIO and KVM_EXIT_OSI, the corresponding operations are complete (and guest state is consistent) only after userspace diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 42bbf41..6d7fe4a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3710,9 +3710,10 @@ int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, ret = kvm_write_guest(vcpu->kvm, gpa, val, bytes); if (ret < 0) - return 0; + return ret; + kvm_mmu_pte_write(vcpu, gpa, val, bytes); - return 1; + return 0; } struct read_write_emulator_ops { @@ -3742,7 +3743,7 @@ static int read_prepare(struct kvm_vcpu *vcpu, void *val, int bytes) static int read_emulate(struct kvm_vcpu *vcpu, gpa_t gpa, void *val, int bytes) { - return !kvm_read_guest(vcpu->kvm, gpa, val, bytes); + return kvm_read_guest(vcpu->kvm, gpa, val, bytes); } static int write_emulate(struct kvm_vcpu *vcpu, gpa_t gpa, @@ -3807,7 +3808,8 @@ static int emulator_read_write_onepage(unsigned long addr, void *val, if (ret) goto mmio; - if (ops->read_write_emulate(vcpu, gpa, val, bytes)) + ret = ops->read_write_emulate(vcpu, gpa, val, bytes); + if (!ret) return X86EMUL_CONTINUE; mmio: @@ -3829,6 +3831,7 @@ mmio: frag->gpa = gpa; frag->data = val; frag->len = now; + frag->write_readonly_mem = (ret == -EPERM); gpa += now; val += now; @@ -3842,8 +3845,8 @@ int emulator_read_write(struct x86_emulate_ctxt *ctxt, unsigned long addr, struct x86_exception *exception, struct read_write_emulator_ops *ops) { + struct kvm_mmio_fragment *frag; struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt); - gpa_t gpa; int rc; if (ops->read_write_prepare && @@ -3875,17 +3878,18 @@ int emulator_read_write(struct x86_emulate_ctxt *ctxt, unsigned long addr, if (!vcpu->mmio_nr_fragments) return rc; - gpa = vcpu->mmio_fragments[0].gpa; + frag = &vcpu->mmio_fragments[0]; vcpu->mmio_needed = 1; vcpu->mmio_cur_fragment = 0; - vcpu->run->mmio.len = vcpu->mmio_fragments[0].len; + vcpu->run->mmio.len = frag->len; vcpu->run->mmio.is_write = vcpu->mmio_is_write = ops->write; vcpu->run->exit_reason = KVM_EXIT_MMIO; - vcpu->run->mmio.phys_addr = gpa; + vcpu->run->mmio.phys_addr = frag->gpa; + vcpu->run->mmio.write_readonly_mem = frag->write_readonly_mem; - return ops->read_write_exit_mmio(vcpu, gpa, val, bytes); + return ops->read_write_exit_mmio(vcpu, frag->gpa, val, bytes); } static int emulator_read_emulated(struct x86_emulate_ctxt *ctxt, @@ -5525,6 +5529,7 @@ static int complete_mmio(struct kvm_vcpu *vcpu) ++frag; run->exit_reason = KVM_EXIT_MMIO; run->mmio.phys_addr = frag->gpa; + vcpu->run->mmio.write_readonly_mem = frag->write_readonly_mem; if (vcpu->mmio_is_write) memcpy(run->mmio.data, frag->data, frag->len); run->mmio.len = frag->len; diff --git a/include/linux/kvm.h b/include/linux/kvm.h index d808694..9d8002f 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -226,6 +226,9 @@ struct kvm_run { __u8 data[8]; __u32 len; __u8 is_write; +#ifdef __KVM_HAVE_READONLY_MEM + __u8 write_readonly_mem; +#endif } mmio; /* KVM_EXIT_HYPERCALL */ struct { diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 5972c98..c37b225 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -189,6 +189,7 @@ struct kvm_mmio_fragment { gpa_t gpa; void *data; unsigned len; + bool write_readonly_mem; }; struct kvm_vcpu { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 3416f8a..0c7def7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1456,6 +1456,9 @@ int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data, unsigned long addr; addr = gfn_to_hva(kvm, gfn); + if (addr == KVM_HVA_ERR_RO_BAD) + return -EPERM; + if (kvm_is_error_hva(addr)) return -EFAULT; r = __copy_to_user((void __user *)addr + offset, data, len); -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
