aboutsummaryrefslogtreecommitdiff
path: root/target-ppc/kvm.c
diff options
context:
space:
mode:
authorDavid Gibson <david@gibson.dropbear.id.au>2011-09-29 21:39:12 +0000
committerAlexander Graf <agraf@suse.de>2011-10-30 17:11:53 +0100
commit0f5cb2989f33059a70e8da335b62af5f27fabbe2 (patch)
treedc8112aaca1611eb9bb733421be27f5947bfcb6d /target-ppc/kvm.c
parent354ac20a36a82a5ee09b0a6c8ba8655358a7597f (diff)
downloadqemu-0f5cb2989f33059a70e8da335b62af5f27fabbe2.zip
qemu-0f5cb2989f33059a70e8da335b62af5f27fabbe2.tar.gz
qemu-0f5cb2989f33059a70e8da335b62af5f27fabbe2.tar.bz2
pseries: Use Book3S-HV TCE acceleration capabilities
The pseries machine of qemu implements the TCE mechanism used as a virtual IOMMU for the PAPR defined virtual IO devices. Because the PAPR spec only defines a small DMA address space, the guest VIO drivers need to update TCE mappings very frequently - the virtual network device is particularly bad. This means many slow exits to qemu to emulate the H_PUT_TCE hypercall. Sufficiently recent kernels allow this to be mitigated by implementing H_PUT_TCE in the host kernel. To make use of this, however, qemu needs to initialize the necessary TCE tables, and map them into itself so that the VIO device implementations can retrieve the mappings when they access guest memory (which is treated as a virtual DMA operation). This patch adds the necessary calls to use the KVM TCE acceleration. If the kernel does not support acceleration, or there is some other error creating the accelerated TCE table, then it will still fall back to full userspace TCE implementation. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'target-ppc/kvm.c')
-rw-r--r--target-ppc/kvm.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index fd17d23..06cad41 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -28,6 +28,7 @@
#include "kvm_ppc.h"
#include "cpu.h"
#include "device_tree.h"
+#include "hw/sysbus.h"
#include "hw/spapr.h"
#include "hw/sysbus.h"
@@ -56,6 +57,7 @@ static int cap_segstate;
static int cap_booke_sregs;
static int cap_ppc_smt;
static int cap_ppc_rma;
+static int cap_spapr_tce;
/* XXX We have a race condition where we actually have a level triggered
* interrupt, but the infrastructure can't expose that yet, so the guest
@@ -81,6 +83,7 @@ int kvm_arch_init(KVMState *s)
cap_booke_sregs = kvm_check_extension(s, KVM_CAP_PPC_BOOKE_SREGS);
cap_ppc_smt = kvm_check_extension(s, KVM_CAP_PPC_SMT);
cap_ppc_rma = kvm_check_extension(s, KVM_CAP_PPC_RMA);
+ cap_spapr_tce = kvm_check_extension(s, KVM_CAP_SPAPR_TCE);
if (!cap_interrupt_level) {
fprintf(stderr, "KVM: Couldn't find level irq capability. Expect the "
@@ -802,6 +805,57 @@ off_t kvmppc_alloc_rma(const char *name, MemoryRegion *sysmem)
return size;
}
+void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t window_size, int *pfd)
+{
+ struct kvm_create_spapr_tce args = {
+ .liobn = liobn,
+ .window_size = window_size,
+ };
+ long len;
+ int fd;
+ void *table;
+
+ if (!cap_spapr_tce) {
+ return NULL;
+ }
+
+ fd = kvm_vm_ioctl(kvm_state, KVM_CREATE_SPAPR_TCE, &args);
+ if (fd < 0) {
+ return NULL;
+ }
+
+ len = (window_size / SPAPR_VIO_TCE_PAGE_SIZE) * sizeof(VIOsPAPR_RTCE);
+ /* FIXME: round this up to page size */
+
+ table = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, 0);
+ if (table == MAP_FAILED) {
+ close(fd);
+ return NULL;
+ }
+
+ *pfd = fd;
+ return table;
+}
+
+int kvmppc_remove_spapr_tce(void *table, int fd, uint32_t window_size)
+{
+ long len;
+
+ if (fd < 0) {
+ return -1;
+ }
+
+ len = (window_size / SPAPR_VIO_TCE_PAGE_SIZE)*sizeof(VIOsPAPR_RTCE);
+ if ((munmap(table, len) < 0) ||
+ (close(fd) < 0)) {
+ fprintf(stderr, "KVM: Unexpected error removing KVM SPAPR TCE "
+ "table: %s", strerror(errno));
+ /* Leak the table */
+ }
+
+ return 0;
+}
+
bool kvm_arch_stop_on_emulation_error(CPUState *env)
{
return true;