Implement a virtual mode handler for the H_CALL H_PAGE_INIT which can be
used to zero or copy a guest page. The page is defined to be 4k and must
be 4k aligned.
The in-kernel handler halves the time to handle this H_CALL compared to
handling it in userspace.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@xxxxxxxxx>
---
arch/powerpc/kvm/book3s_hv.c | 38 ++++++++++++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 5a066fc299e1..25bf1f3680f2 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -801,6 +801,38 @@ static int kvmppc_h_set_mode(struct kvm_vcpu *vcpu, unsigned long mflags,
}
}
+static int kvmppc_h_page_init(struct kvm_vcpu *vcpu, unsigned long flags,
+ unsigned long dest, unsigned long src)
+{
+ int ret = H_FUNCTION;
+ u64 pg_sz = 1UL << 12; /* 4K page size */
+ u64 pg_mask = pg_sz - 1;
+
+ /* Check for invalid flags (H_PAGE_SET_LOANED covers all CMO flags) */
+ if (flags & ~(H_ICACHE_INVALIDATE | H_ICACHE_SYNCHRONIZE |
+ H_ZERO_PAGE | H_COPY_PAGE | H_PAGE_SET_LOANED))
+ return H_PARAMETER;
+
+ /* dest (and src if copy_page flag set) must be page aligned */
+ if ((dest & pg_mask) || ((flags & H_COPY_PAGE) && (src & pg_mask)))
+ return H_PARAMETER;
+
+ /* Either zero or copy the page as determined by the flags */
+ if (flags & H_ZERO_PAGE) {
+ ret = kvm_clear_guest(vcpu->kvm, dest, pg_sz);
+ if (ret < 0)
+ return H_PARAMETER;
+ } else if (flags & H_COPY_PAGE) {
+ ret = kvm_copy_guest(vcpu->kvm, dest, src, pg_sz);
+ if (ret < 0)
+ return H_PARAMETER;
+ }
+
+ /* We can ignore the remaining flags */
+
+ return H_SUCCESS;
+}
+
static int kvm_arch_vcpu_yield_to(struct kvm_vcpu *target)
{
struct kvmppc_vcore *vcore = target->arch.vcore;
@@ -1001,6 +1033,11 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
if (nesting_enabled(vcpu->kvm))
ret = kvmhv_copy_tofrom_guest_nested(vcpu);
break;
+ case H_PAGE_INIT:
+ ret = kvmppc_h_page_init(vcpu, kvmppc_get_gpr(vcpu, 4),
+ kvmppc_get_gpr(vcpu, 5),
+ kvmppc_get_gpr(vcpu, 6));
+ break;
default:
return RESUME_HOST;
}
@@ -1045,6 +1082,7 @@ static int kvmppc_hcall_impl_hv(unsigned long cmd)
case H_IPOLL:
case H_XIRR_X:
#endif
+ case H_PAGE_INIT:
return 1;
}
--
2.13.6
