xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: PPC: Improve split mode

Browse Source 
When in split mode, instruction relocation and data relocation are not equal.

So far we implemented this mode by reserving a special pseudo-VSID for the
two cases and flushing all PTEs when going into split mode, which is slow.

Unfortunately 32bit Linux and Mac OS X use split mode extensively. So to not
slow down things too much, I came up with a different idea: Mark the split
mode with a bit in the VSID and then treat it like any other segment.

This means we can just flush the shadow segment cache, but keep the PTEs
intact. I verified that this works with ppc32 Linux and Mac OS X 10.4
guests and does speed them up.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Alexander Graf
2010-04-20 02:49:48 +02:00
committed by Avi Kivity
parent 7fdaec997c
commit f7bc74e1c3
4 changed files with 52 additions and 45 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
arch/powerpc/kvm/book3s_32_mmu.c
View File

@@ -330,30 +330,35 @@ static void kvmppc_mmu_book3s_32_tlbie(struct kvm_vcpu *vcpu, ulong ea, bool lar
static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
u64 *vsid)
{
ulong ea = esid << SID_SHIFT;
struct kvmppc_sr *sr;
u64 gvsid = esid;
if (vcpu->arch.msr & (MSR_DR|MSR_IR)) {
sr = find_sr(to_book3s(vcpu), ea);
if (sr->valid)
gvsid = sr->vsid;
}
/* In case we only have one of MSR_IR or MSR_DR set, let's put
that in the real-mode context (and hope RM doesn't access
high memory) */
switch (vcpu->arch.msr & (MSR_DR|MSR_IR)) {
case 0:
*vsid = (VSID_REAL >> 16) | esid;
*vsid = VSID_REAL | esid;
break;
case MSR_IR:
*vsid = (VSID_REAL_IR >> 16) | esid;
*vsid = VSID_REAL_IR | gvsid;
break;
case MSR_DR:
*vsid = (VSID_REAL_DR >> 16) | esid;
*vsid = VSID_REAL_DR | gvsid;
break;
case MSR_DR|MSR_IR:
{
ulong ea = esid << SID_SHIFT;
struct kvmppc_sr *sr = find_sr(to_book3s(vcpu), ea);
if (!sr->valid)
return -1;
*vsid = sr->vsid;
break;
}
default:
BUG();
}