From: Jan Beulich <jbeul...@suse.com>
In preparation of the introduction of new vCPU operations allowing to
register the respective areas (one of the two is x86-specific) by
guest-physical address, add the necessary fork handling (with the
backing function yet to be filled in).
Signed-off-by: Jan Beulich <jbeul...@suse.com>
Signed-off-by: Roger Pau Monné <roger....@citrix.com>
---
Changes since v4:
- Rely on map_guest_area() to populate the child p2m if necessary.
---
xen/arch/x86/mm/mem_sharing.c | 31 +++++++++++++++++++++++++++++++
xen/common/domain.c | 7 +++++++
2 files changed, 38 insertions(+)
diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c
index 5f8f1fb4d871..99cf001fd70f 100644
--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -1641,6 +1641,24 @@ static void copy_vcpu_nonreg_state(struct vcpu *d_vcpu,
struct vcpu *cd_vcpu)
hvm_set_nonreg_state(cd_vcpu, &nrs);
}
+static int copy_guest_area(struct guest_area *cd_area,
+ const struct guest_area *d_area,
+ struct vcpu *cd_vcpu,
+ const struct domain *d)
+{
+ unsigned int offset;
+
+ /* Check if no area to map, or already mapped. */
+ if ( !d_area->pg || cd_area->pg )
+ return 0;
+
+ offset = PAGE_OFFSET(d_area->map);
+ return map_guest_area(cd_vcpu, gfn_to_gaddr(
+ mfn_to_gfn(d, page_to_mfn(d_area->pg)))
+
+ offset,
+ PAGE_SIZE - offset, cd_area, NULL);
+}
+
static int copy_vpmu(struct vcpu *d_vcpu, struct vcpu *cd_vcpu)
{
struct vpmu_struct *d_vpmu = vcpu_vpmu(d_vcpu);
@@ -1709,6 +1727,16 @@ static int copy_vcpu_settings(struct domain *cd, const
struct domain *d)
return ret;
}
+ /* Same for the (physically registered) runstate and time info areas.
*/
+ ret = copy_guest_area(&cd_vcpu->runstate_guest_area,
+ &d_vcpu->runstate_guest_area, cd_vcpu, d);
+ if ( ret )
+ return ret;
+ ret = copy_guest_area(&cd_vcpu->arch.time_guest_area,
+ &d_vcpu->arch.time_guest_area, cd_vcpu, d);
+ if ( ret )
+ return ret;
+
ret = copy_vpmu(d_vcpu, cd_vcpu);
if ( ret )
return ret;
@@ -1950,7 +1978,10 @@ int mem_sharing_fork_reset(struct domain *d, bool
reset_state,
state:
if ( reset_state )
+ {
rc = copy_settings(d, pd);
+ /* TBD: What to do here with -ERESTART? */
+ }
domain_unpause(d);
diff --git a/xen/common/domain.c b/xen/common/domain.c
index d4958ec5e149..47fc90271901 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -1601,6 +1601,13 @@ void unmap_vcpu_info(struct vcpu *v)
put_page_and_type(mfn_to_page(mfn));
}
+int map_guest_area(struct vcpu *v, paddr_t gaddr, unsigned int size,
+ struct guest_area *area,
+ void (*populate)(void *dst, struct vcpu *v))
+{
+ return -EOPNOTSUPP;
+}
+
/*
* This is only intended to be used for domain cleanup (or more generally only
* with at least the respective vCPU, if it's not the current one, reliably
--
2.42.0
