From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de (cantor2.suse.de [195.135.220.15]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx2.suse.de", Issuer "CAcert Class 3 Root" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 0A3EF100803 for ; Sat, 18 Feb 2012 04:14:12 +1100 (EST) From: Alexander Graf To: kvm-ppc@vger.kernel.org Subject: [PATCH 29/30] KVM: PPC: bookehv: disable MAS register updates early Date: Fri, 17 Feb 2012 18:13:56 +0100 Message-Id: <1329498837-11717-30-git-send-email-agraf@suse.de> In-Reply-To: <1329498837-11717-1-git-send-email-agraf@suse.de> References: <1329498837-11717-1-git-send-email-agraf@suse.de> Cc: Scott Wood , linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , We need to make sure that no MAS updates happen automatically while we have the guest MAS registers loaded. So move the disabling code a bit higher up so that it covers the full time we have guest values in MAS registers. The race this patch fixes should never occur, but it makes the code a bit more logical to do it this way around. Signed-off-by: Alexander Graf --- arch/powerpc/kvm/bookehv_interrupts.S | 10 ++++++---- 1 files changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kvm/bookehv_interrupts.S b/arch/powerpc/kvm/bookehv_interrupts.S index 8a297c3..7d558a8 100644 --- a/arch/powerpc/kvm/bookehv_interrupts.S +++ b/arch/powerpc/kvm/bookehv_interrupts.S @@ -358,6 +358,7 @@ _GLOBAL(kvmppc_resume_host) mtspr SPRN_MAS4, r6 stw r5, VCPU_SHARED_MAS7_3+0(r11) mtspr SPRN_MAS6, r8 + /* Enable MAS register updates via exception */ mfspr r3, SPRN_EPCR rlwinm r3, r3, 0, ~SPRN_EPCR_DMIUH mtspr SPRN_EPCR, r3 @@ -515,6 +516,11 @@ lightweight_exit: mtspr SPRN_PID, r3 PPC_LL r11, VCPU_SHARED(r4) + /* Disable MAS register updates via exception */ + mfspr r3, SPRN_EPCR + oris r3, r3, SPRN_EPCR_DMIUH@h + mtspr SPRN_EPCR, r3 + isync /* Save host mas4 and mas6 and load guest MAS registers */ mfspr r3, SPRN_MAS4 stw r3, VCPU_HOST_MAS4(r4) @@ -538,10 +544,6 @@ lightweight_exit: lwz r5, VCPU_SHARED_MAS7_3+0(r11) mtspr SPRN_MAS6, r3 mtspr SPRN_MAS7, r5 - /* Disable MAS register updates via exception */ - mfspr r3, SPRN_EPCR - oris r3, r3, SPRN_EPCR_DMIUH@h - mtspr SPRN_EPCR, r3 /* * Host interrupt handlers may have clobbered these guest-readable -- 1.6.0.2