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| author | James Hogan <james.hogan@imgtec.com> | 2016-07-04 19:35:11 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-07-05 16:09:14 +0200 |
| commit | 70e92c7ee94094d2db8bfe225a8c9b1bde89c26d (patch) | |
| tree | be4f2ba4705ed81862392378fb220d6d0b840fd1 /arch/mips/kvm/entry.c | |
| parent | d85ebff0073c783f0c74dc0e08c348f6f2d807c7 (diff) | |
| download | linux-70e92c7ee94094d2db8bfe225a8c9b1bde89c26d.tar.gz linux-70e92c7ee94094d2db8bfe225a8c9b1bde89c26d.tar.bz2 linux-70e92c7ee94094d2db8bfe225a8c9b1bde89c26d.zip | |
MIPS: KVM: Don't save/restore lo/hi for r6
MIPSr6 doesn't have lo/hi registers, so don't bother saving or
restoring them, and don't expose them to userland with the KVM ioctl
interface either.
In fact the lo/hi registers aren't callee saved in the MIPS ABIs anyway,
so there is no need to preserve the host lo/hi values at all when
transitioning to and from the guest (which happens via a function call).
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim KrÄmář <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/mips/kvm/entry.c')
| -rw-r--r-- | arch/mips/kvm/entry.c | 16 |
1 files changed, 4 insertions, 12 deletions
diff --git a/arch/mips/kvm/entry.c b/arch/mips/kvm/entry.c index de8b6ec5573f..75ba7c2ecb3d 100644 --- a/arch/mips/kvm/entry.c +++ b/arch/mips/kvm/entry.c @@ -178,12 +178,6 @@ void *kvm_mips_build_vcpu_run(void *addr) UASM_i_SW(&p, i, offsetof(struct pt_regs, regs[i]), K1); } - /* Save hi/lo */ - uasm_i_mflo(&p, V0); - UASM_i_SW(&p, V0, offsetof(struct pt_regs, lo), K1); - uasm_i_mfhi(&p, V1); - UASM_i_SW(&p, V1, offsetof(struct pt_regs, hi), K1); - /* Save host status */ uasm_i_mfc0(&p, V0, C0_STATUS); UASM_i_SW(&p, V0, offsetof(struct pt_regs, cp0_status), K1); @@ -307,12 +301,14 @@ static void *kvm_mips_build_enter_guest(void *addr) UASM_i_LW(&p, i, offsetof(struct kvm_vcpu_arch, gprs[i]), K1); } +#ifndef CONFIG_CPU_MIPSR6 /* Restore hi/lo */ UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu_arch, hi), K1); uasm_i_mthi(&p, K0); UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu_arch, lo), K1); uasm_i_mtlo(&p, K0); +#endif /* Restore the guest's k0/k1 registers */ UASM_i_LW(&p, K0, offsetof(struct kvm_vcpu_arch, gprs[K0]), K1); @@ -408,12 +404,14 @@ void *kvm_mips_build_exit(void *addr) UASM_i_SW(&p, i, offsetof(struct kvm_vcpu_arch, gprs[i]), K1); } +#ifndef CONFIG_CPU_MIPSR6 /* We need to save hi/lo and restore them on the way out */ uasm_i_mfhi(&p, T0); UASM_i_SW(&p, T0, offsetof(struct kvm_vcpu_arch, hi), K1); uasm_i_mflo(&p, T0); UASM_i_SW(&p, T0, offsetof(struct kvm_vcpu_arch, lo), K1); +#endif /* Finally save guest k1 to VCPU */ uasm_i_ehb(&p); @@ -663,12 +661,6 @@ static void *kvm_mips_build_ret_to_host(void *addr) UASM_i_LW(&p, i, offsetof(struct pt_regs, regs[i]), K1); } - UASM_i_LW(&p, K0, offsetof(struct pt_regs, hi), K1); - uasm_i_mthi(&p, K0); - - UASM_i_LW(&p, K0, offsetof(struct pt_regs, lo), K1); - uasm_i_mtlo(&p, K0); - /* Restore RDHWR access */ UASM_i_LA_mostly(&p, K0, (long)&hwrena); uasm_i_lw(&p, K0, uasm_rel_lo((long)&hwrena), K0); |