From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.7 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 29F3B7D2F0 for ; Mon, 12 Aug 2019 10:39:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727846AbfHLKjU (ORCPT ); Mon, 12 Aug 2019 06:39:20 -0400 Received: from foss.arm.com ([217.140.110.172]:47986 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727323AbfHLKjU (ORCPT ); Mon, 12 Aug 2019 06:39:20 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A0EAD1715; Mon, 12 Aug 2019 03:39:19 -0700 (PDT) Received: from [10.1.196.133] (e112269-lin.cambridge.arm.com [10.1.196.133]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 250763F706; Mon, 12 Aug 2019 03:39:18 -0700 (PDT) From: Steven Price Subject: Re: [PATCH 9/9] arm64: Retrieve stolen time as paravirtualized guest To: Zenghui Yu Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Catalin Marinas , linux-doc@vger.kernel.org, Russell King , linux-arm-kernel@lists.infradead.org, Marc Zyngier , Paolo Bonzini , Will Deacon , kvmarm@lists.cs.columbia.edu References: <20190802145017.42543-1-steven.price@arm.com> <20190802145017.42543-10-steven.price@arm.com> <5d763c8e-9c06-c448-2644-25bfa0e57e8c@huawei.com> Message-ID: <07075994-3a32-8f20-23d8-1759ec2874e3@arm.com> Date: Mon, 12 Aug 2019 11:39:16 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <5d763c8e-9c06-c448-2644-25bfa0e57e8c@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 8bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 09/08/2019 14:51, Zenghui Yu wrote: [...] > Hi Steven, > > Since userspace is not involved yet (right?), no one will create the > PV_TIME device for guest (and no one will specify the IPA of the shared > stolen time region), and I guess we will get a "not supported" error > here. > > So what should we do if we want to test this series now?  Any userspace > tools?  If no, do you have any plans for userspace developing? ;-) At the moment I have the following patch to kvmtool which creates the PV_TIME device - this isn't in a state to go upstream, and Marc has asked that I rework the memory allocation, so this will need to change. It's a little ugly as it simply reserves the first page of RAM to use for the PV time structures. ----8<---- diff --git a/Makefile b/Makefile index 3862112..a79956b 100644 --- a/Makefile +++ b/Makefile @@ -158,7 +158,7 @@ endif # ARM OBJS_ARM_COMMON := arm/fdt.o arm/gic.o arm/gicv2m.o arm/ioport.o \ arm/kvm.o arm/kvm-cpu.o arm/pci.o arm/timer.o \ - arm/pmu.o + arm/pmu.o arm/pvtime.o HDRS_ARM_COMMON := arm/include ifeq ($(ARCH), arm) DEFINES += -DCONFIG_ARM diff --git a/arm/fdt.c b/arm/fdt.c index c80e6da..19eccbc 100644 --- a/arm/fdt.c +++ b/arm/fdt.c @@ -119,6 +119,7 @@ static int setup_fdt(struct kvm *kvm) /* Create new tree without a reserve map */ _FDT(fdt_create(fdt, FDT_MAX_SIZE)); + _FDT(fdt_add_reservemap_entry(fdt, kvm->arch.memory_guest_start, 4096)); _FDT(fdt_finish_reservemap(fdt)); /* Header */ diff --git a/arm/kvm.c b/arm/kvm.c index 1f85fc6..8bbfef1 100644 --- a/arm/kvm.c +++ b/arm/kvm.c @@ -11,6 +11,8 @@ #include #include +int pvtime_create(struct kvm *kvm); + struct kvm_ext kvm_req_ext[] = { { DEFINE_KVM_EXT(KVM_CAP_IRQCHIP) }, { DEFINE_KVM_EXT(KVM_CAP_ONE_REG) }, @@ -86,6 +88,10 @@ void kvm__arch_init(struct kvm *kvm, const char *hugetlbfs_path, u64 ram_size) /* Create the virtual GIC. */ if (gic__create(kvm, kvm->cfg.arch.irqchip)) die("Failed to create virtual GIC"); + + /* Setup PV time */ + if (pvtime_create(kvm)) + die("Failed to initialise PV time"); } #define FDT_ALIGN SZ_2M diff --git a/arm/pvtime.c b/arm/pvtime.c new file mode 100644 index 0000000..abcaab3 --- /dev/null +++ b/arm/pvtime.c @@ -0,0 +1,77 @@ +#include "kvm/kvm.h" + +#define KVM_DEV_TYPE_ARM_PV_TIME (KVM_DEV_TYPE_ARM_VGIC_ITS+2) + +/* Device Control API: PV_TIME */ +#define KVM_DEV_ARM_PV_TIME_PADDR 0 +#define KVM_DEV_ARM_PV_TIME_FREQUENCY 3 + +#define KVM_DEV_ARM_PV_TIME_ST 0 +#define KVM_DEV_ARM_PV_TIME_LPT 1 + +static int pvtime_fd; + +int pvtime_create(struct kvm *kvm); + +int pvtime_create(struct kvm *kvm) +{ + int err; + u64 lpt_paddr = 0x10000000; + u64 st_paddr = lpt_paddr + 4096; + u32 frequency = 100 * 1000 * 1000; + + printf("lpt_paddr=%llx\n", lpt_paddr); + + struct kvm_create_device pvtime_device = { + .type = KVM_DEV_TYPE_ARM_PV_TIME, + .flags = 0, + }; + + err = ioctl(kvm->vm_fd, KVM_CREATE_DEVICE, &pvtime_device); + if (err) { + printf("Failed to create PV device\n"); + return 0; + } + + pvtime_fd = pvtime_device.fd; + + struct kvm_device_attr lpt_base = { + .group = KVM_DEV_ARM_PV_TIME_PADDR, + .attr = KVM_DEV_ARM_PV_TIME_LPT, + .addr = (u64)(unsigned long)&lpt_paddr + }; + struct kvm_device_attr st_base = { + .group = KVM_DEV_ARM_PV_TIME_PADDR, + .attr = KVM_DEV_ARM_PV_TIME_ST, + .addr = (u64)(unsigned long)&st_paddr + }; + + struct kvm_device_attr lpt_freq = { + .group = KVM_DEV_ARM_PV_TIME_FREQUENCY, + .attr = KVM_DEV_ARM_PV_TIME_LPT, + .addr = (u64)(unsigned long)&frequency + }; + + err = ioctl(pvtime_fd, KVM_SET_DEVICE_ATTR, &lpt_base); + if (err) { + perror("ioctl lpt_base failed"); + printf("Ignoring LPT...\n"); + } + err = ioctl(pvtime_fd, KVM_SET_DEVICE_ATTR, &st_base); + if (err) { + perror("ioctl st_base failed"); + goto out_err; + } + err = ioctl(pvtime_fd, KVM_SET_DEVICE_ATTR, &lpt_freq); + if (err) { + perror("ioctl lpt_freq failed"); + printf("Ignoring LPT...\n"); + } + + printf("PV time setup\n"); + + return 0; +out_err: + close(pvtime_fd); + return err; +}