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| author |   Paul Mackerras <paulus@samba.org> | 2013-09-20 14:52:43 +1000 |
|---|---|---|
| committer |   Alexander Graf <agraf@suse.de> | 2013-10-17 14:45:03 +0200 |
| commit | a2d56020d1d91934e7bb3e7c8a5a3b5921ce121b (patch) | |
| tree | cebd5519ec61284b8db1ddddfc31236aab6c7628 /arch/powerpc/kvm/book3s_rmhandlers.S | |
| parent | KVM: PPC: Book3S PR: Fix compilation without CONFIG_ALTIVEC (diff) | |
| download | wireguard-linux-a2d56020d1d91934e7bb3e7c8a5a3b5921ce121b.tar.xz wireguard-linux-a2d56020d1d91934e7bb3e7c8a5a3b5921ce121b.zip | |
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu
Currently PR-style KVM keeps the volatile guest register values
(R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than
the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two
places, a kmalloc'd struct and in the PACA, and it gets copied back
and forth in kvmppc_core_vcpu_load/put(), because the real-mode code
can't rely on being able to access the kmalloc'd struct.
This changes the code to copy the volatile values into the shadow_vcpu
as one of the last things done before entering the guest. Similarly
the values are copied back out of the shadow_vcpu to the kvm_vcpu
immediately after exiting the guest. We arrange for interrupts to be
still disabled at this point so that we can't get preempted on 64-bit
and end up copying values from the wrong PACA.
This means that the accessor functions in kvm_book3s.h for these
registers are greatly simplified, and are same between PR and HV KVM.
In places where accesses to shadow_vcpu fields are now replaced by
accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs.
Finally, on 64-bit, we don't need the kmalloc'd struct at all any more.
With this, the time to read the PVR one million times in a loop went
from 567.7ms to 575.5ms (averages of 6 values), an increase of about
1.4% for this worse-case test for guest entries and exits. The
standard deviation of the measurements is about 11ms, so the
difference is only marginally significant statistically.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'arch/powerpc/kvm/book3s_rmhandlers.S')
| -rw-r--r-- | arch/powerpc/kvm/book3s_rmhandlers.S | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/powerpc/kvm/book3s_rmhandlers.S b/arch/powerpc/kvm/book3s_rmhandlers.S index 8f7633e3afb8..cd59a3a38482 100644 --- a/arch/powerpc/kvm/book3s_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_rmhandlers.S @@ -179,11 +179,15 @@ _GLOBAL(kvmppc_entry_trampoline) li r6, MSR_IR | MSR_DR andc r6, r5, r6 /* Clear DR and IR in MSR value */ +#ifdef CONFIG_PPC_BOOK3S_32 /* * Set EE in HOST_MSR so that it's enabled when we get into our - * C exit handler function + * C exit handler function. On 64-bit we delay enabling + * interrupts until we have finished transferring stuff + * to or from the PACA. */ ori r5, r5, MSR_EE +#endif mtsrr0 r7 mtsrr1 r6 RFI |