On Thu, Jan 21, 2016 at 06:39:37PM +1100, Alexey Kardashevskiy wrote:
This adds real and virtual mode handlers for the H_PUT_TCE_INDIRECT and
H_STUFF_TCE hypercalls for user space emulated devices such as IBMVIO
devices or emulated PCI. These calls allow adding multiple entries
(up to 512) into the TCE table in one call which saves time on
transition between kernel and user space.
This implements the KVM_CAP_PPC_MULTITCE capability. When present,
the kernel will try handling H_PUT_TCE_INDIRECT and H_STUFF_TCE.
If they can not be handled by the kernel, they are passed on to
the user space. The user space still has to have an implementation
for these.
Both HV and PR-syle KVM are supported.
Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
[snip]
diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
index 975f0ab..987f406 100644
--- a/arch/powerpc/kvm/book3s_64_vio.c
+++ b/arch/powerpc/kvm/book3s_64_vio.c
@@ -14,6 +14,7 @@
*
* Copyright 2010 Paul Mackerras, IBM Corp. <paulus@xxxxxxxxxxx>
* Copyright 2011 David Gibson, IBM Corporation <dwg@xxxxxxxxxxx>
+ * Copyright 2016 Alexey Kardashevskiy, IBM Corporation <aik@xxxxxxxxxxx>
*/
#include <linux/types.h>
@@ -37,8 +38,7 @@
#include <asm/kvm_host.h>
#include <asm/udbg.h>
#include <asm/iommu.h>
-
-#define TCES_PER_PAGE (PAGE_SIZE / sizeof(u64))
+#include <asm/tce.h>
static unsigned long kvmppc_stt_npages(unsigned long window_size)
{
@@ -200,3 +200,109 @@ fail:
}
return ret;
}
+
+long kvmppc_h_put_tce(struct kvm_vcpu *vcpu,
+ unsigned long liobn, unsigned long ioba,
+ unsigned long tce)
+{
+ long ret;
+ struct kvmppc_spapr_tce_table *stt;
+
+ stt = kvmppc_find_table(vcpu, liobn);
+ if (!stt)
+ return H_TOO_HARD;
+
+ ret = kvmppc_ioba_validate(stt, ioba, 1);
+ if (ret != H_SUCCESS)
+ return ret;
+
+ ret = kvmppc_tce_validate(stt, tce);
+ if (ret != H_SUCCESS)
+ return ret;
+
+ kvmppc_tce_put(stt, ioba >> IOMMU_PAGE_SHIFT_4K, tce);
+
+ return H_SUCCESS;
+}
+EXPORT_SYMBOL_GPL(kvmppc_h_put_tce);
As far as I can see, this is functionally identical to the
kvmppc_h_put_tce that we have in book3s_64_vio_hv.c, that gets renamed
later on in this patch. It would be good to have an explanation in
the commit message why we want two almost-identical functions (and
similarly for kvmppc_h_stuff_tce). Is it because a future patch is
going to make them different, for instance?
+long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu,
+ unsigned long liobn, unsigned long ioba,
+ unsigned long tce_value, unsigned long npages)
+{
+ struct kvmppc_spapr_tce_table *stt;
+ long i, ret;
+
+ stt = kvmppc_find_table(vcpu, liobn);
+ if (!stt)
+ return H_TOO_HARD;
+
+ ret = kvmppc_ioba_validate(stt, ioba, npages);
+ if (ret != H_SUCCESS)
+ return ret;
+
+ if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ))
+ return H_PARAMETER;
+
+ for (i = 0; i < npages; ++i, ioba += IOMMU_PAGE_SIZE_4K)
Looks like we need a bounds check on npages, presumably in
kvmppc_ioba_validate().
diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c
index 8cd3a95..58c63ed 100644
--- a/arch/powerpc/kvm/book3s_64_vio_hv.c
+++ b/arch/powerpc/kvm/book3s_64_vio_hv.c
[...]
+long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu,
+ unsigned long liobn, unsigned long ioba,
+ unsigned long tce_list, unsigned long npages)
+{
+ struct kvmppc_spapr_tce_table *stt;
+ long i, ret = H_SUCCESS;
+ unsigned long tces, entry, ua = 0;
+ unsigned long *rmap = NULL;
+
+ stt = kvmppc_find_table(vcpu, liobn);
+ if (!stt)
+ return H_TOO_HARD;
+
+ entry = ioba >> IOMMU_PAGE_SHIFT_4K;
+ /*
+ * The spec says that the maximum size of the list is 512 TCEs
+ * so the whole table addressed resides in 4K page
+ */
+ if (npages > 512)
+ return H_PARAMETER;
+
+ if (tce_list & (SZ_4K - 1))
+ return H_PARAMETER;
+
+ ret = kvmppc_ioba_validate(stt, ioba, npages);
+ if (ret != H_SUCCESS)
+ return ret;
+
+ if (kvmppc_gpa_to_ua(vcpu->kvm, tce_list, &ua, &rmap))
+ return H_TOO_HARD;
+
+ rmap = (void *) vmalloc_to_phys(rmap);
+
+ lock_rmap(rmap);
A comment here explaining why we lock the rmap and what that achieves
would be useful for future generations.
