linux_dsm_epyc7002/arch/s390/kvm/pv.c
Janosch Frank 1ed576a20c KVM: s390: pv: Mark mm as protected after the set secure parameters and improve cleanup
We can only have protected guest pages after a successful set secure
parameters call as only then the UV allows imports and unpacks.

By moving the test we can now also check for it in s390_reset_acc()
and do an early return if it is 0.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Fixes: 29b40f105e ("KVM: s390: protvirt: Add initial vm and cpu lifecycle handling")
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-11-11 09:31:48 +01:00

304 lines
8.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Hosting Protected Virtual Machines
*
* Copyright IBM Corp. 2019, 2020
* Author(s): Janosch Frank <frankja@linux.ibm.com>
*/
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/pagemap.h>
#include <linux/sched/signal.h>
#include <asm/gmap.h>
#include <asm/uv.h>
#include <asm/mman.h>
#include "kvm-s390.h"
int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
{
int cc = 0;
if (kvm_s390_pv_cpu_get_handle(vcpu)) {
cc = uv_cmd_nodata(kvm_s390_pv_cpu_get_handle(vcpu),
UVC_CMD_DESTROY_SEC_CPU, rc, rrc);
KVM_UV_EVENT(vcpu->kvm, 3,
"PROTVIRT DESTROY VCPU %d: rc %x rrc %x",
vcpu->vcpu_id, *rc, *rrc);
WARN_ONCE(cc, "protvirt destroy cpu failed rc %x rrc %x",
*rc, *rrc);
}
/* Intended memory leak for something that should never happen. */
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;
}
int kvm_s390_pv_create_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
{
struct uv_cb_csc uvcb = {
.header.cmd = UVC_CMD_CREATE_SEC_CPU,
.header.len = sizeof(uvcb),
};
int cc;
if (kvm_s390_pv_cpu_get_handle(vcpu))
return -EINVAL;
vcpu->arch.pv.stor_base = __get_free_pages(GFP_KERNEL,
get_order(uv_info.guest_cpu_stor_len));
if (!vcpu->arch.pv.stor_base)
return -ENOMEM;
/* Input */
uvcb.guest_handle = kvm_s390_pv_get_handle(vcpu->kvm);
uvcb.num = vcpu->arch.sie_block->icpua;
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;
KVM_UV_EVENT(vcpu->kvm, 3,
"PROTVIRT CREATE VCPU: cpu %d handle %llx rc %x rrc %x",
vcpu->vcpu_id, uvcb.cpu_handle, uvcb.header.rc,
uvcb.header.rrc);
if (cc) {
u16 dummy;
kvm_s390_pv_destroy_cpu(vcpu, &dummy, &dummy);
return -EIO;
}
/* Output */
vcpu->arch.pv.handle = uvcb.cpu_handle;
vcpu->arch.sie_block->pv_handle_cpu = uvcb.cpu_handle;
vcpu->arch.sie_block->pv_handle_config = kvm_s390_pv_get_handle(vcpu->kvm);
vcpu->arch.sie_block->sdf = 2;
kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
return 0;
}
/* only free resources when the destroy was successful */
static void kvm_s390_pv_dealloc_vm(struct kvm *kvm)
{
vfree(kvm->arch.pv.stor_var);
free_pages(kvm->arch.pv.stor_base,
get_order(uv_info.guest_base_stor_len));
memset(&kvm->arch.pv, 0, sizeof(kvm->arch.pv));
}
static int kvm_s390_pv_alloc_vm(struct kvm *kvm)
{
unsigned long base = uv_info.guest_base_stor_len;
unsigned long virt = uv_info.guest_virt_var_stor_len;
unsigned long npages = 0, vlen = 0;
struct kvm_memory_slot *memslot;
kvm->arch.pv.stor_var = NULL;
kvm->arch.pv.stor_base = __get_free_pages(GFP_KERNEL, get_order(base));
if (!kvm->arch.pv.stor_base)
return -ENOMEM;
/*
* Calculate current guest storage for allocation of the
* variable storage, which is based on the length in MB.
*
* Slots are sorted by GFN
*/
mutex_lock(&kvm->slots_lock);
memslot = kvm_memslots(kvm)->memslots;
npages = memslot->base_gfn + memslot->npages;
mutex_unlock(&kvm->slots_lock);
kvm->arch.pv.guest_len = npages * PAGE_SIZE;
/* Allocate variable storage */
vlen = ALIGN(virt * ((npages * PAGE_SIZE) / HPAGE_SIZE), PAGE_SIZE);
vlen += uv_info.guest_virt_base_stor_len;
kvm->arch.pv.stor_var = vzalloc(vlen);
if (!kvm->arch.pv.stor_var)
goto out_err;
return 0;
out_err:
kvm_s390_pv_dealloc_vm(kvm);
return -ENOMEM;
}
/* this should not fail, but if it does, we must not free the donated memory */
int kvm_s390_pv_deinit_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
{
int cc;
/* make all pages accessible before destroying the guest */
s390_reset_acc(kvm->mm);
cc = uv_cmd_nodata(kvm_s390_pv_get_handle(kvm),
UVC_CMD_DESTROY_SEC_CONF, rc, rrc);
WRITE_ONCE(kvm->arch.gmap->guest_handle, 0);
atomic_set(&kvm->mm->context.is_protected, 0);
KVM_UV_EVENT(kvm, 3, "PROTVIRT DESTROY VM: rc %x rrc %x", *rc, *rrc);
WARN_ONCE(cc, "protvirt destroy vm failed rc %x rrc %x", *rc, *rrc);
/* Inteded memory leak on "impossible" error */
if (!cc)
kvm_s390_pv_dealloc_vm(kvm);
return cc ? -EIO : 0;
}
int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
{
struct uv_cb_cgc uvcb = {
.header.cmd = UVC_CMD_CREATE_SEC_CONF,
.header.len = sizeof(uvcb)
};
int cc, ret;
u16 dummy;
ret = kvm_s390_pv_alloc_vm(kvm);
if (ret)
return ret;
/* Inputs */
uvcb.guest_stor_origin = 0; /* MSO is 0 for KVM */
uvcb.guest_stor_len = kvm->arch.pv.guest_len;
uvcb.guest_asce = kvm->arch.gmap->asce;
uvcb.guest_sca = (unsigned long)kvm->arch.sca;
uvcb.conf_base_stor_origin = (u64)kvm->arch.pv.stor_base;
uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var;
cc = uv_call(0, (u64)&uvcb);
*rc = uvcb.header.rc;
*rrc = uvcb.header.rrc;
KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x",
uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc);
/* Outputs */
kvm->arch.pv.handle = uvcb.guest_handle;
if (cc) {
if (uvcb.header.rc & UVC_RC_NEED_DESTROY)
kvm_s390_pv_deinit_vm(kvm, &dummy, &dummy);
else
kvm_s390_pv_dealloc_vm(kvm);
return -EIO;
}
kvm->arch.gmap->guest_handle = uvcb.guest_handle;
return 0;
}
int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
u16 *rrc)
{
struct uv_cb_ssc uvcb = {
.header.cmd = UVC_CMD_SET_SEC_CONF_PARAMS,
.header.len = sizeof(uvcb),
.sec_header_origin = (u64)hdr,
.sec_header_len = length,
.guest_handle = kvm_s390_pv_get_handle(kvm),
};
int cc = uv_call(0, (u64)&uvcb);
*rc = uvcb.header.rc;
*rrc = uvcb.header.rrc;
KVM_UV_EVENT(kvm, 3, "PROTVIRT VM SET PARMS: rc %x rrc %x",
*rc, *rrc);
if (!cc)
atomic_set(&kvm->mm->context.is_protected, 1);
return cc ? -EINVAL : 0;
}
static int unpack_one(struct kvm *kvm, unsigned long addr, u64 tweak,
u64 offset, u16 *rc, u16 *rrc)
{
struct uv_cb_unp uvcb = {
.header.cmd = UVC_CMD_UNPACK_IMG,
.header.len = sizeof(uvcb),
.guest_handle = kvm_s390_pv_get_handle(kvm),
.gaddr = addr,
.tweak[0] = tweak,
.tweak[1] = offset,
};
int ret = gmap_make_secure(kvm->arch.gmap, addr, &uvcb);
*rc = uvcb.header.rc;
*rrc = uvcb.header.rrc;
if (ret && ret != -EAGAIN)
KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: failed addr %llx with rc %x rrc %x",
uvcb.gaddr, *rc, *rrc);
return ret;
}
int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
unsigned long tweak, u16 *rc, u16 *rrc)
{
u64 offset = 0;
int ret = 0;
if (addr & ~PAGE_MASK || !size || size & ~PAGE_MASK)
return -EINVAL;
KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: start addr %lx size %lx",
addr, size);
while (offset < size) {
ret = unpack_one(kvm, addr, tweak, offset, rc, rrc);
if (ret == -EAGAIN) {
cond_resched();
if (fatal_signal_pending(current))
break;
continue;
}
if (ret)
break;
addr += PAGE_SIZE;
offset += PAGE_SIZE;
}
if (!ret)
KVM_UV_EVENT(kvm, 3, "%s", "PROTVIRT VM UNPACK: successful");
return ret;
}
int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state)
{
struct uv_cb_cpu_set_state uvcb = {
.header.cmd = UVC_CMD_CPU_SET_STATE,
.header.len = sizeof(uvcb),
.cpu_handle = kvm_s390_pv_cpu_get_handle(vcpu),
.state = state,
};
int cc;
cc = uv_call(0, (u64)&uvcb);
KVM_UV_EVENT(vcpu->kvm, 3, "PROTVIRT SET CPU %d STATE %d rc %x rrc %x",
vcpu->vcpu_id, state, uvcb.header.rc, uvcb.header.rrc);
if (cc)
return -EINVAL;
return 0;
}