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| author | Janosch Frank <frankja@linux.ibm.com> | 2019-04-02 09:21:06 +0200 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2020-02-27 19:47:11 +0100 |
| commit | 19e1227768863a1469797c13ef8fea1af7beac2c (patch) | |
| tree | a3982c53f1e0c20916d32369ca3602b18c768719 /arch/s390/kvm/pv.c | |
| parent | c8aac2344d663ec9c635ccec368341602f255f4c (diff) | |
| download | linux-19e1227768863a1469797c13ef8fea1af7beac2c.tar.bz2 | |
KVM: S390: protvirt: Introduce instruction data area bounce buffer
Now that we can't access guest memory anymore, we have a dedicated
satellite block that's a bounce buffer for instruction data.
We re-use the memop interface to copy the instruction data to / from
userspace. This lets us re-use a lot of QEMU code which used that
interface to make logical guest memory accesses which are not possible
anymore in protected mode anyway.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/kvm/pv.c')
| -rw-r--r-- | arch/s390/kvm/pv.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c index 9840ee49e572..13a41533eacf 100644 --- a/arch/s390/kvm/pv.c +++ b/arch/s390/kvm/pv.c @@ -33,10 +33,18 @@ int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc) if (!cc) free_pages(vcpu->arch.pv.stor_base, get_order(uv_info.guest_cpu_stor_len)); + + free_page(sida_origin(vcpu->arch.sie_block)); vcpu->arch.sie_block->pv_handle_cpu = 0; vcpu->arch.sie_block->pv_handle_config = 0; memset(&vcpu->arch.pv, 0, sizeof(vcpu->arch.pv)); vcpu->arch.sie_block->sdf = 0; + /* + * The sidad field (for sdf == 2) is now the gbea field (for sdf == 0). + * Use the reset value of gbea to avoid leaking the kernel pointer of + * the just freed sida. + */ + vcpu->arch.sie_block->gbea = 1; kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); return cc ? EIO : 0; @@ -64,6 +72,14 @@ int kvm_s390_pv_create_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc) uvcb.state_origin = (u64)vcpu->arch.sie_block; uvcb.stor_origin = (u64)vcpu->arch.pv.stor_base; + /* Alloc Secure Instruction Data Area Designation */ + vcpu->arch.sie_block->sidad = __get_free_page(GFP_KERNEL | __GFP_ZERO); + if (!vcpu->arch.sie_block->sidad) { + free_pages(vcpu->arch.pv.stor_base, + get_order(uv_info.guest_cpu_stor_len)); + return -ENOMEM; + } + cc = uv_call(0, (u64)&uvcb); *rc = uvcb.header.rc; *rrc = uvcb.header.rrc; |