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authorBharat Bhushan <r65777@freescale.com>2012-08-09 00:38:19 +0400
committerAlexander Graf <agraf@suse.de>2012-10-06 01:38:47 +0400
commitf61c94bb99ca4253ac5dd57750e1af209a4beb7a (patch)
tree348d15c584a683cd805ed71ed5c8a81848d24e70 /arch/powerpc/kvm/booke_emulate.c
parent7c973a2ebb8fb9c8ee2ae9647f9ad7b0ad58a3e6 (diff)
downloadlinux-f61c94bb99ca4253ac5dd57750e1af209a4beb7a.tar.xz
KVM: PPC: booke: Add watchdog emulation
This patch adds the watchdog emulation in KVM. The watchdog emulation is enabled by KVM_ENABLE_CAP(KVM_CAP_PPC_BOOKE_WATCHDOG) ioctl. The kernel timer are used for watchdog emulation and emulates h/w watchdog state machine. On watchdog timer expiry, it exit to QEMU if TCR.WRC is non ZERO. QEMU can reset/shutdown etc depending upon how it is configured. Signed-off-by: Liu Yu <yu.liu@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com> [bharat.bhushan@freescale.com: reworked patch] Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> [agraf: adjust to new request framework] Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'arch/powerpc/kvm/booke_emulate.c')
-rw-r--r--arch/powerpc/kvm/booke_emulate.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/booke_emulate.c b/arch/powerpc/kvm/booke_emulate.c
index 12834bb608ab..5a66ade7fd17 100644
--- a/arch/powerpc/kvm/booke_emulate.c
+++ b/arch/powerpc/kvm/booke_emulate.c
@@ -145,6 +145,14 @@ int kvmppc_booke_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, ulong spr_val)
kvmppc_clr_tsr_bits(vcpu, spr_val);
break;
case SPRN_TCR:
+ /*
+ * WRC is a 2-bit field that is supposed to preserve its
+ * value once written to non-zero.
+ */
+ if (vcpu->arch.tcr & TCR_WRC_MASK) {
+ spr_val &= ~TCR_WRC_MASK;
+ spr_val |= vcpu->arch.tcr & TCR_WRC_MASK;
+ }
kvmppc_set_tcr(vcpu, spr_val);
break;