From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B7E9C48BE5 for ; Fri, 21 Jun 2019 09:40:12 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id C2CBC21530 for ; Fri, 21 Jun 2019 09:40:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C2CBC21530 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 76A854A4CA; Fri, 21 Jun 2019 05:40:11 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id KmOxpK7QUFcs; Fri, 21 Jun 2019 05:40:10 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 2F7DF4A331; Fri, 21 Jun 2019 05:40:10 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 63B184A52C for ; Fri, 21 Jun 2019 05:40:08 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id b8OlkINokOK3 for ; Fri, 21 Jun 2019 05:40:07 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 6BA544A4E1 for ; Fri, 21 Jun 2019 05:40:04 -0400 (EDT) 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 3C3B3147A; Fri, 21 Jun 2019 02:40:04 -0700 (PDT) Received: from filthy-habits.cambridge.arm.com (filthy-habits.cambridge.arm.com [10.1.197.61]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DB53A3F246; Fri, 21 Jun 2019 02:40:02 -0700 (PDT) From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Subject: [PATCH 33/59] KVM: arm64: nv: Pretend we only support larger-than-host page sizes Date: Fri, 21 Jun 2019 10:38:17 +0100 Message-Id: <20190621093843.220980-34-marc.zyngier@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190621093843.220980-1-marc.zyngier@arm.com> References: <20190621093843.220980-1-marc.zyngier@arm.com> MIME-Version: 1.0 Cc: Andre Przywara , Dave Martin X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu From: Jintack Lim Exposing memory management support to the virtual EL2 as is exposed to the host hypervisor would make the implementation too complex and inefficient. Therefore expose limited memory management support for the following two cases. We expose same or larger page granules than the one host uses. We can theoretically support a guest hypervisor having smaller-than-host granularities but it is not worth it since it makes the implementation complicated and it would waste memory. We expose 40 bits of physical address range to the virtual EL2, because we only support a 40bit IPA for the guest. Eventually, this will change. [ This was only trapping on the 32-bit encoding, also using the current target register value as a base for the sanitisation. Use as the handler for the 64-bit sysreg as well, also load the sanitised version of the sysreg before clearing and setting bits. -- Andre Przywara ] Signed-off-by: Jintack Lim Signed-off-by: Andre Przywara Signed-off-by: Marc Zyngier --- arch/arm64/kvm/sys_regs.c | 50 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index ec34b81da936..cc994ec3c121 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1710,6 +1710,54 @@ static bool access_spsr_el2(struct kvm_vcpu *vcpu, return true; } +static bool access_id_aa64mmfr0_el1(struct kvm_vcpu *v, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + u64 val; + + if (p->is_write) + return write_to_read_only(v, p, r); + + val = read_id_reg(v, r, false); + + if (!nested_virt_in_use(v)) + goto out; + + /* + * Don't expose granules smaller than the host's granule to the guest. + * We can theoretically support a guest hypervisor having + * smaller-than-host granularities but it is not worth it since it + * makes the implementation complicated and it would waste memory. + */ + switch (PAGE_SIZE) { + case SZ_64K: + /* 16KB granule not supported */ + val &= ~(0xf << ID_AA64MMFR0_TGRAN16_SHIFT); + val |= (ID_AA64MMFR0_TGRAN16_NI << ID_AA64MMFR0_TGRAN16_SHIFT); + /* fall through */ + case SZ_16K: + /* 4KB granule not supported */ + val &= ~(0xf << ID_AA64MMFR0_TGRAN4_SHIFT); + val |= (ID_AA64MMFR0_TGRAN4_NI << ID_AA64MMFR0_TGRAN4_SHIFT); + break; + case SZ_4K: + /* All granule sizes are supported */ + break; + default: + unreachable(); + } + + /* Expose only 40 bits physical address range to the guest hypervisor */ + val &= ~(0xf << ID_AA64MMFR0_PARANGE_SHIFT); + val |= (0x2 << ID_AA64MMFR0_PARANGE_SHIFT); /* 40 bits */ + +out: + p->regval = val; + + return true; +} + static bool access_id_aa64pfr0_el1(struct kvm_vcpu *v, struct sys_reg_params *p, const struct sys_reg_desc *r) @@ -1846,7 +1894,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { ID_UNALLOCATED(6,7), /* CRm=7 */ - ID_SANITISED(ID_AA64MMFR0_EL1), + ID_SANITISED_FN(ID_AA64MMFR0_EL1, access_id_aa64mmfr0_el1), ID_SANITISED(ID_AA64MMFR1_EL1), ID_SANITISED(ID_AA64MMFR2_EL1), ID_UNALLOCATED(7,3), -- 2.20.1 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm