diff options
| author |   James Hogan <james.hogan@imgtec.com> | 2016-05-06 14:36:22 +0100 |
|---|---|---|
| committer |   Ralf Baechle <ralf@linux-mips.org> | 2016-05-13 14:02:19 +0200 |
| commit | f1b711c638c7df56112eff8e9661c91202782516 (patch) | |
| tree | 499012a7401da027907354e8ede36b3fbc65a7f1 | |
| parent | MIPS: KVM/locore.S: Only preserve callee saved registers (diff) | |
| download | linux-dev-f1b711c638c7df56112eff8e9661c91202782516.tar.xz linux-dev-f1b711c638c7df56112eff8e9661c91202782516.zip | |
MIPS: KVM/locore.S: Relax noat
Now that the at register ($1) is no longer saved by
__kvm_mips_vcpu_run(), relax the noat assembler directive so that it
only applies around code where at is restored before entering guest, and
saved after exiting guest.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13209/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| -rw-r--r-- | arch/mips/kvm/locore.S | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/arch/mips/kvm/locore.S b/arch/mips/kvm/locore.S index 3ea522e4954b..1f2167bc847d 100644 --- a/arch/mips/kvm/locore.S +++ b/arch/mips/kvm/locore.S @@ -48,7 +48,6 @@ * a1: vcpu */ .set noreorder - .set noat FEXPORT(__kvm_mips_vcpu_run) /* k0/k1 not being used in host kernel context */ @@ -145,6 +144,7 @@ FEXPORT(__kvm_mips_load_asid) /* Disable RDHWR access */ mtc0 zero, CP0_HWRENA + .set noat /* Now load up the Guest Context from VCPU */ LONG_L $1, VCPU_R1(k1) LONG_L $2, VCPU_R2(k1) @@ -256,6 +256,8 @@ NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra) LONG_S $30, VCPU_R30(k1) LONG_S $31, VCPU_R31(k1) + .set at + /* We need to save hi/lo and restore them on the way out */ mfhi t0 LONG_S t0, VCPU_HI(k1) @@ -307,9 +309,7 @@ NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra) /* load up the host EBASE */ mfc0 v0, CP0_STATUS - .set at or k0, v0, ST0_BEV - .set noat mtc0 k0, CP0_STATUS ehb @@ -321,7 +321,6 @@ NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra) * If FPU is enabled, save FCR31 and clear it so that later ctc1's don't * trigger FPE for pending exceptions. */ - .set at and v1, v0, ST0_CU1 beqz v1, 1f nop @@ -331,7 +330,6 @@ NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra) sw t0, VCPU_FCR31(k1) ctc1 zero,fcr31 .set pop - .set noat 1: #ifdef CONFIG_CPU_HAS_MSA @@ -354,10 +352,8 @@ NESTED (MIPSX(GuestException), CALLFRAME_SIZ, ra) #endif /* Now that the new EBASE has been loaded, unset BEV and KSU_USER */ - .set at and v0, v0, ~(ST0_EXL | KSU_USER | ST0_IE) or v0, v0, ST0_CU0 - .set noat mtc0 v0, CP0_STATUS ehb @@ -424,18 +420,14 @@ __kvm_mips_return_to_guest: /* Switch EBASE back to the one used by KVM */ mfc0 v1, CP0_STATUS - .set at or k0, v1, ST0_BEV - .set noat mtc0 k0, CP0_STATUS ehb mtc0 t0, CP0_EBASE /* Setup status register for running guest in UM */ - .set at or v1, v1, (ST0_EXL | KSU_USER | ST0_IE) and v1, v1, ~(ST0_CU0 | ST0_MX) - .set noat mtc0 v1, CP0_STATUS ehb @@ -464,6 +456,7 @@ __kvm_mips_return_to_guest: /* Disable RDHWR access */ mtc0 zero, CP0_HWRENA + .set noat /* load the guest context from VCPU and return */ LONG_L $0, VCPU_R0(k1) LONG_L $1, VCPU_R1(k1) @@ -509,6 +502,7 @@ FEXPORT(__kvm_mips_skip_guest_restore) LONG_L k1, VCPU_R27(k1) eret + .set at __kvm_mips_return_to_host: /* EBASE is already pointing to Linux */ |