From bb25b9ba3e33e941dc48048d0a784e6a05e5648a Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Sun, 24 Jul 2011 10:48:17 +0200 Subject: [PATCH] [S390] kvm: handle tprot intercepts When running a kvm guest we can get intercepts for tprot, if the host page table is read-only or not populated. This patch implements the most common case (linux memory detection). This also allows host copy on write for guest memory on newer systems. Signed-off-by: Christian Borntraeger Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/kvm_host.h | 1 + arch/s390/kvm/intercept.c | 1 + arch/s390/kvm/kvm-s390.c | 1 + arch/s390/kvm/kvm-s390.h | 1 + arch/s390/kvm/priv.c | 49 ++++++++++++++++++++++++++++++++++++++++ 5 files changed, 53 insertions(+) diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index cef7dbf..e9bcdca 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -138,6 +138,7 @@ struct kvm_vcpu_stat { u32 instruction_chsc; u32 instruction_stsi; u32 instruction_stfl; + u32 instruction_tprot; u32 instruction_sigp_sense; u32 instruction_sigp_emergency; u32 instruction_sigp_stop; diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index f7b6df4..b531205 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -105,6 +105,7 @@ static intercept_handler_t instruction_handlers[256] = { [0xae] = kvm_s390_handle_sigp, [0xb2] = kvm_s390_handle_b2, [0xb7] = handle_lctl, + [0xe5] = kvm_s390_handle_e5, [0xeb] = handle_lctlg, }; diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 67345ae..123ebea 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -62,6 +62,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { { "instruction_chsc", VCPU_STAT(instruction_chsc) }, { "instruction_stsi", VCPU_STAT(instruction_stsi) }, { "instruction_stfl", VCPU_STAT(instruction_stfl) }, + { "instruction_tprot", VCPU_STAT(instruction_tprot) }, { "instruction_sigp_sense", VCPU_STAT(instruction_sigp_sense) }, { "instruction_sigp_emergency", VCPU_STAT(instruction_sigp_emergency) }, { "instruction_sigp_stop", VCPU_STAT(instruction_sigp_stop) }, diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index a7b7586..65e2201 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -87,6 +87,7 @@ static inline void kvm_s390_vcpu_set_mem(struct kvm_vcpu *vcpu) /* implemented in priv.c */ int kvm_s390_handle_b2(struct kvm_vcpu *vcpu); +int kvm_s390_handle_e5(struct kvm_vcpu *vcpu); /* implemented in sigp.c */ int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu); diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index 73c47bd..3916263 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -326,3 +326,52 @@ int kvm_s390_handle_b2(struct kvm_vcpu *vcpu) } return -EOPNOTSUPP; } + +static int handle_tprot(struct kvm_vcpu *vcpu) +{ + int base1 = (vcpu->arch.sie_block->ipb & 0xf0000000) >> 28; + int disp1 = (vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16; + int base2 = (vcpu->arch.sie_block->ipb & 0xf000) >> 12; + int disp2 = vcpu->arch.sie_block->ipb & 0x0fff; + u64 address1 = disp1 + base1 ? vcpu->arch.guest_gprs[base1] : 0; + u64 address2 = disp2 + base2 ? vcpu->arch.guest_gprs[base2] : 0; + struct vm_area_struct *vma; + + vcpu->stat.instruction_tprot++; + + /* we only handle the Linux memory detection case: + * access key == 0 + * guest DAT == off + * everything else goes to userspace. */ + if (address2 & 0xf0) + return -EOPNOTSUPP; + if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT) + return -EOPNOTSUPP; + + + down_read(¤t->mm->mmap_sem); + vma = find_vma(current->mm, + (unsigned long) __guestaddr_to_user(vcpu, address1)); + if (!vma) { + up_read(¤t->mm->mmap_sem); + return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); + } + + vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44); + if (!(vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_READ)) + vcpu->arch.sie_block->gpsw.mask |= (1ul << 44); + if (!(vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_READ)) + vcpu->arch.sie_block->gpsw.mask |= (2ul << 44); + + up_read(¤t->mm->mmap_sem); + return 0; +} + +int kvm_s390_handle_e5(struct kvm_vcpu *vcpu) +{ + /* For e5xx... instructions we only handle TPROT */ + if ((vcpu->arch.sie_block->ipa & 0x00ff) == 0x01) + return handle_tprot(vcpu); + return -EOPNOTSUPP; +} + -- 2.7.4