From patchwork Tue Nov 26 21:13:24 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Kubascik X-Patchwork-Id: 11263073 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2ECBB930 for ; Tue, 26 Nov 2019 21:15:03 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1088E2071E for ; Tue, 26 Nov 2019 21:15:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1088E2071E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=dornerworks.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iZi9P-0006Bz-Av; Tue, 26 Nov 2019 21:13:35 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iZi9N-0006BS-Nb for xen-devel@lists.xenproject.org; Tue, 26 Nov 2019 21:13:33 +0000 X-Inumbo-ID: 990e1d9f-1091-11ea-a3a9-12813bfff9fa Received: from webmail.dornerworks.com (unknown [12.207.209.150]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTP id 990e1d9f-1091-11ea-a3a9-12813bfff9fa; Tue, 26 Nov 2019 21:13:32 +0000 (UTC) From: Jeff Kubascik To: Date: Tue, 26 Nov 2019 16:13:24 -0500 Message-ID: <20191126211324.122736-1-jeff.kubascik@dornerworks.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [172.27.13.171] X-ClientProxiedBy: Mcbain.dw.local (172.27.1.45) To Mcbain.dw.local (172.27.1.45) X-spam-status: No, score=-2.9 required=3.5 tests=ALL_TRUSTED, BAYES_00, MAILSHELL_SCORE_0_4 X-Spam-Flag: NO Subject: [Xen-devel] [PATCH v2] xen/arm: remove physical timer offset X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stewart Hildebrand , Volodymyr Babchuk , Stefano Stabellini , Julien Grall Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" The physical timer traps apply an offset so that time starts at 0 for the guest. However, this offset is not currently applied to the physical counter. Per the ARMv8 Reference Manual (ARM DDI 0487E.a), section D11.2.4 Timers, the "Offset" between the counter and timer should be zero for a physical timer. This removes the offset to make the timer and counter consistent. Furthermore, section D11.2.4 specifies that the values in the TimerValue view of the timers are signed in standard two's complement form. When writing to the TimerValue register, it should be signed extended as described by the equation CompareValue = (Counter[63:0] + SignExtend(TimerValue))[63:0] Signed-off-by: Jeff Kubascik --- Changes in v2: - Update commit message to specify reference manual version and section - Change physical timer cval to hold hardware value - Make sure to sign extend TimerValue on writes. This was done by first casting the r pointer to (int32_t *), dereferencing it, then casting to uint64_t. Please let me know if there is a more correct way to do this --- xen/arch/arm/vtimer.c | 21 +++++++++------------ xen/include/asm-arm/domain.h | 3 --- 2 files changed, 9 insertions(+), 15 deletions(-) diff --git a/xen/arch/arm/vtimer.c b/xen/arch/arm/vtimer.c index e6aebdac9e..eb12a08acf 100644 --- a/xen/arch/arm/vtimer.c +++ b/xen/arch/arm/vtimer.c @@ -62,7 +62,6 @@ static void virt_timer_expired(void *data) int domain_vtimer_init(struct domain *d, struct xen_arch_domainconfig *config) { - d->arch.phys_timer_base.offset = NOW(); d->arch.virt_timer_base.offset = READ_SYSREG64(CNTPCT_EL0); d->time_offset_seconds = ticks_to_ns(d->arch.virt_timer_base.offset - boot_count); do_div(d->time_offset_seconds, 1000000000); @@ -185,7 +184,7 @@ static bool vtimer_cntp_ctl(struct cpu_user_regs *regs, uint32_t *r, bool read) if ( v->arch.phys_timer.ctl & CNTx_CTL_ENABLE ) { set_timer(&v->arch.phys_timer.timer, - v->arch.phys_timer.cval + v->domain->arch.phys_timer_base.offset); + ticks_to_ns(v->arch.phys_timer.cval - boot_count)); } else stop_timer(&v->arch.phys_timer.timer); @@ -197,26 +196,25 @@ static bool vtimer_cntp_tval(struct cpu_user_regs *regs, uint32_t *r, bool read) { struct vcpu *v = current; - s_time_t now; + uint64_t cntpct; if ( !ACCESS_ALLOWED(regs, EL0PTEN) ) return false; - now = NOW() - v->domain->arch.phys_timer_base.offset; + cntpct = get_cycles(); if ( read ) { - *r = (uint32_t)(ns_to_ticks(v->arch.phys_timer.cval - now) & 0xffffffffull); + *r = (uint32_t)((v->arch.phys_timer.cval - cntpct) & 0xffffffffull); } else { - v->arch.phys_timer.cval = now + ticks_to_ns(*r); + v->arch.phys_timer.cval = cntpct + (uint64_t)(*((int32_t *)r)); if ( v->arch.phys_timer.ctl & CNTx_CTL_ENABLE ) { v->arch.phys_timer.ctl &= ~CNTx_CTL_PENDING; set_timer(&v->arch.phys_timer.timer, - v->arch.phys_timer.cval + - v->domain->arch.phys_timer_base.offset); + ticks_to_ns(v->arch.phys_timer.cval - boot_count)); } } return true; @@ -232,17 +230,16 @@ static bool vtimer_cntp_cval(struct cpu_user_regs *regs, uint64_t *r, if ( read ) { - *r = ns_to_ticks(v->arch.phys_timer.cval); + *r = v->arch.phys_timer.cval; } else { - v->arch.phys_timer.cval = ticks_to_ns(*r); + v->arch.phys_timer.cval = *r; if ( v->arch.phys_timer.ctl & CNTx_CTL_ENABLE ) { v->arch.phys_timer.ctl &= ~CNTx_CTL_PENDING; set_timer(&v->arch.phys_timer.timer, - v->arch.phys_timer.cval + - v->domain->arch.phys_timer_base.offset); + ticks_to_ns(v->arch.phys_timer.cval - boot_count)); } } return true; diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h index 86ebdd2bcf..16a7150a95 100644 --- a/xen/include/asm-arm/domain.h +++ b/xen/include/asm-arm/domain.h @@ -65,9 +65,6 @@ struct arch_domain RELMEM_done, } relmem; - struct { - uint64_t offset; - } phys_timer_base; struct { uint64_t offset; } virt_timer_base;