From 76d072fb05f646eb180f161bbe06ab185af52f38 Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Wed, 11 Jun 2014 10:37:52 +0200 Subject: [PATCH] KVM: PPC: Book3S HV: Access XICS in BE On the exit path from the guest we check what type of interrupt we received if we received one. This means we're doing hardware access to the XICS interrupt controller. However, when running on a little endian system, this access is byte reversed. So let's make sure to swizzle the bytes back again and virtually make XICS accesses big endian. Signed-off-by: Alexander Graf --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index bf5270ef09a..364ca0c0615 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -2350,7 +2350,18 @@ kvmppc_read_intr: cmpdi r6, 0 beq- 1f lwzcix r0, r6, r7 - rlwinm. r3, r0, 0, 0xffffff + /* + * Save XIRR for later. Since we get in in reverse endian on LE + * systems, save it byte reversed and fetch it back in host endian. + */ + li r3, HSTATE_SAVED_XIRR + STWX_BE r0, r3, r13 +#ifdef __LITTLE_ENDIAN__ + lwz r3, HSTATE_SAVED_XIRR(r13) +#else + mr r3, r0 +#endif + rlwinm. r3, r3, 0, 0xffffff sync beq 1f /* if nothing pending in the ICP */ @@ -2382,10 +2393,9 @@ kvmppc_read_intr: li r3, -1 1: blr -42: /* It's not an IPI and it's for the host, stash it in the PACA - * before exit, it will be picked up by the host ICP driver +42: /* It's not an IPI and it's for the host. We saved a copy of XIRR in + * the PACA earlier, it will be picked up by the host ICP driver */ - stw r0, HSTATE_SAVED_XIRR(r13) li r3, 1 b 1b -- 2.46.0