[v1 4/5] KVM: s390: sida: sort out physical vs virtual pointers usage

Nico Boehr
2022-10-20T14:33:42Z

All callers of the sida_origin() macro actually expected a virtual
address, so rename it to sida_addr() and hand out a virtual address.

At some places, the macro wasn't used, potentially creating problems
if the sida size ever becomes nonzero (not currently the case), so let's
start using it everywhere now while at it.

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
arch/s390/include/asm/kvm_host.h | 3 +--
arch/s390/kvm/intercept.c | 7 +++----
arch/s390/kvm/kvm-s390.c | 9 +++++----
arch/s390/kvm/priv.c | 3 +--
arch/s390/kvm/pv.c | 8 +++++---
5 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 931f97875899..21f1339a4197 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -142,8 +142,7 @@ struct mcck_volatile_info {
CR14_EXTERNAL_DAMAGE_SUBMASK)

#define SIDAD_SIZE_MASK 0xff
-#define sida_origin(sie_block) \
- ((sie_block)->sidad & PAGE_MASK)
+#define sida_addr(sie_block) phys_to_virt((sie_block)->sidad & PAGE_MASK)
#define sida_size(sie_block) \
((((sie_block)->sidad & SIDAD_SIZE_MASK) + 1) * PAGE_SIZE)

diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index b703b5202f25..0ee02dae14b2 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -409,8 +409,7 @@ int handle_sthyi(struct kvm_vcpu *vcpu)
out:
if (!cc) {
if (kvm_s390_pv_cpu_is_protected(vcpu)) {
- memcpy((void *)(sida_origin(vcpu->arch.sie_block)),
- sctns, PAGE_SIZE);
+ memcpy(sida_addr(vcpu->arch.sie_block), sctns, PAGE_SIZE);
} else {
r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
if (r) {
@@ -464,7 +463,7 @@ static int handle_operexc(struct kvm_vcpu *vcpu)

static int handle_pv_spx(struct kvm_vcpu *vcpu)
{
- u32 pref = *(u32 *)vcpu->arch.sie_block->sidad;
+ u32 pref = *(u32 *)sida_addr(vcpu->arch.sie_block);

kvm_s390_set_prefix(vcpu, pref);
trace_kvm_s390_handle_prefix(vcpu, 1, pref);
@@ -497,7 +496,7 @@ static int handle_pv_sclp(struct kvm_vcpu *vcpu)

static int handle_pv_uvc(struct kvm_vcpu *vcpu)
{
- struct uv_cb_share *guest_uvcb = (void *)vcpu->arch.sie_block->sidad;
+ struct uv_cb_share *guest_uvcb = sida_addr(vcpu->arch.sie_block);
struct uv_cb_cts uvcb = {
.header.cmd = UVC_CMD_UNPIN_PAGE_SHARED,
.header.len = sizeof(uvcb),
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 0f7ff0c9019f..bd6e0201bfe5 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -5167,6 +5167,7 @@ static long kvm_s390_vcpu_sida_op(struct kvm_vcpu *vcpu,
struct kvm_s390_mem_op *mop)
{
void __user *uaddr = (void __user *)mop->buf;
+ void *sida_addr;
int r = 0;

if (mop->flags || !mop->size)
@@ -5178,16 +5179,16 @@ static long kvm_s390_vcpu_sida_op(struct kvm_vcpu *vcpu,
if (!kvm_s390_pv_cpu_is_protected(vcpu))
return -EINVAL;

+ sida_addr = (char *)sida_addr(vcpu->arch.sie_block) + mop->sida_offset;
+
switch (mop->op) {
case KVM_S390_MEMOP_SIDA_READ:
- if (copy_to_user(uaddr, (void *)(sida_origin(vcpu->arch.sie_block) +
- mop->sida_offset), mop->size))
+ if (copy_to_user(uaddr, sida_addr, mop->size))
r = -EFAULT;

break;
case KVM_S390_MEMOP_SIDA_WRITE:
- if (copy_from_user((void *)(sida_origin(vcpu->arch.sie_block) +
- mop->sida_offset), uaddr, mop->size))
+ if (copy_from_user(sida_addr, uaddr, mop->size))
r = -EFAULT;
break;
}
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 3335fa09b6f1..9f8a192bd750 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -924,8 +924,7 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
return -EREMOTE;
}
if (kvm_s390_pv_cpu_is_protected(vcpu)) {
- memcpy((void *)sida_origin(vcpu->arch.sie_block), (void *)mem,
- PAGE_SIZE);
+ memcpy(sida_addr(vcpu->arch.sie_block), (void *)mem, PAGE_SIZE);
rc = 0;
} else {
rc = write_guest(vcpu, operand2, ar, (void *)mem, PAGE_SIZE);
diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index 7cb7799a0acb..c7435c37cdfe 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -44,7 +44,7 @@ int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
free_pages(vcpu->arch.pv.stor_base,
get_order(uv_info.guest_cpu_stor_len));

- free_page(sida_origin(vcpu->arch.sie_block));
+ free_page((unsigned long)sida_addr(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));
@@ -66,6 +66,7 @@ int kvm_s390_pv_create_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
.header.cmd = UVC_CMD_CREATE_SEC_CPU,
.header.len = sizeof(uvcb),
};
+ void *sida_addr;
int cc;

if (kvm_s390_pv_cpu_get_handle(vcpu))
@@ -83,12 +84,13 @@ int kvm_s390_pv_create_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
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_ACCOUNT | __GFP_ZERO);
- if (!vcpu->arch.sie_block->sidad) {
+ sida_addr = (void *)__get_free_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
+ if (!sida_addr) {
free_pages(vcpu->arch.pv.stor_base,
get_order(uv_info.guest_cpu_stor_len));
return -ENOMEM;
}
+ vcpu->arch.sie_block->sidad = virt_to_phys(sida_addr);

cc = uv_call(0, (u64)&uvcb);
*rc = uvcb.header.rc;
--
2.37.3