From patchwork Thu May 21 16:19:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 11563417 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 C7BE2739 for ; Thu, 21 May 2020 16:21:45 +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 9554D20759 for ; Thu, 21 May 2020 16:21:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=xen.org header.i=@xen.org header.b="0UcGuSWj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9554D20759 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xen.org Authentication-Results: mail.kernel.org; spf=pass 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 4.92) (envelope-from ) id 1jbnvL-0000ys-Ac; Thu, 21 May 2020 16:19:59 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jbnvK-0000yS-3T for xen-devel@lists.xenproject.org; Thu, 21 May 2020 16:19:58 +0000 X-Inumbo-ID: e3bbed44-9b7e-11ea-b9cf-bc764e2007e4 Received: from mail.xenproject.org (unknown [104.130.215.37]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id e3bbed44-9b7e-11ea-b9cf-bc764e2007e4; Thu, 21 May 2020 16:19:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=QfGmoXyhQuN/EVxQAxJlmVEjrcceHfUNWPHkPI0BpEQ=; b=0UcGuSWjabQ6qD4s4WMXkM5UJm JhbRjcH0xTpYT6vGQcXaa9L+rYKNtWZl+1l1QbYX6R7eyVmkvkdN7KxdYhlOncJYTSTGO5Dxp3BrJ 0JttAfT/5a3/Ng6JM8HMSd98J56qjwLtU0GCMlV6CFzimu4OY9Hy3bk8h8aXIGq8IzUw=; Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jbnv8-0006ne-1u; Thu, 21 May 2020 16:19:46 +0000 Received: from 54-240-197-224.amazon.com ([54.240.197.224] helo=u2f063a87eabd5f.cbg10.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1jbnv7-00088L-OK; Thu, 21 May 2020 16:19:45 +0000 From: Paul Durrant To: xen-devel@lists.xenproject.org Subject: [PATCH v5 2/5] xen/common/domctl: introduce XEN_DOMCTL_get/setdomaincontext Date: Thu, 21 May 2020 17:19:36 +0100 Message-Id: <20200521161939.4508-3-paul@xen.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200521161939.4508-1-paul@xen.org> References: <20200521161939.4508-1-paul@xen.org> MIME-Version: 1.0 X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , Paul Durrant , Andrew Cooper , Paul Durrant , Ian Jackson , George Dunlap , Jan Beulich , Daniel De Graaf Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" These domctls provide a mechanism to get and set domain context from the toolstack. Signed-off-by: Paul Durrant Reviewed-by: Julien Grall --- Cc: Daniel De Graaf Cc: Ian Jackson Cc: Wei Liu Cc: Andrew Cooper Cc: George Dunlap Cc: Jan Beulich Cc: Stefano Stabellini v4: - Add missing zero pad checks v3: - Addressed comments from Julien and Jan - Use vmalloc() rather than xmalloc_bytes() v2: - drop mask parameter - const-ify some more buffers --- tools/flask/policy/modules/xen.if | 4 +- tools/libxc/include/xenctrl.h | 5 + tools/libxc/xc_domain.c | 56 +++++++++ xen/common/domctl.c | 173 ++++++++++++++++++++++++++++ xen/include/public/domctl.h | 41 +++++++ xen/xsm/flask/hooks.c | 6 + xen/xsm/flask/policy/access_vectors | 4 + 7 files changed, 287 insertions(+), 2 deletions(-) diff --git a/tools/flask/policy/modules/xen.if b/tools/flask/policy/modules/xen.if index 8eb2293a52..2bc9db4f64 100644 --- a/tools/flask/policy/modules/xen.if +++ b/tools/flask/policy/modules/xen.if @@ -53,7 +53,7 @@ define(`create_domain_common', ` allow $1 $2:domain2 { set_cpu_policy settsc setscheduler setclaim set_vnumainfo get_vnumainfo cacheflush psr_cmt_op psr_alloc soft_reset - resource_map get_cpu_policy }; + resource_map get_cpu_policy setcontext }; allow $1 $2:security check_context; allow $1 $2:shadow enable; allow $1 $2:mmu { map_read map_write adjust memorymap physmap pinpage mmuext_op updatemp }; @@ -97,7 +97,7 @@ define(`migrate_domain_out', ` allow $1 $2:hvm { gethvmc getparam }; allow $1 $2:mmu { stat pageinfo map_read }; allow $1 $2:domain { getaddrsize getvcpucontext pause destroy }; - allow $1 $2:domain2 gettsc; + allow $1 $2:domain2 { gettsc getcontext }; allow $1 $2:shadow { enable disable logdirty }; ') diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h index 45ff7db1e8..0ce2372e2f 100644 --- a/tools/libxc/include/xenctrl.h +++ b/tools/libxc/include/xenctrl.h @@ -867,6 +867,11 @@ int xc_domain_hvm_setcontext(xc_interface *xch, uint8_t *hvm_ctxt, uint32_t size); +int xc_domain_getcontext(xc_interface *xch, uint32_t domid, + void *ctxt_buf, size_t *size); +int xc_domain_setcontext(xc_interface *xch, uint32_t domid, + const void *ctxt_buf, size_t size); + /** * This function will return guest IO ABI protocol * diff --git a/tools/libxc/xc_domain.c b/tools/libxc/xc_domain.c index 71829c2bce..e462a6f728 100644 --- a/tools/libxc/xc_domain.c +++ b/tools/libxc/xc_domain.c @@ -537,6 +537,62 @@ int xc_domain_hvm_setcontext(xc_interface *xch, return ret; } +int xc_domain_getcontext(xc_interface *xch, uint32_t domid, + void *ctxt_buf, size_t *size) +{ + int ret; + DECLARE_DOMCTL = { + .cmd = XEN_DOMCTL_getdomaincontext, + .domain = domid, + .u.getdomaincontext.size = *size, + }; + DECLARE_HYPERCALL_BOUNCE(ctxt_buf, *size, XC_HYPERCALL_BUFFER_BOUNCE_OUT); + + if ( xc_hypercall_bounce_pre(xch, ctxt_buf) ) + return -1; + + set_xen_guest_handle(domctl.u.setdomaincontext.buffer, ctxt_buf); + + ret = do_domctl(xch, &domctl); + + xc_hypercall_bounce_post(xch, ctxt_buf); + + if ( ret ) + return ret; + + *size = domctl.u.getdomaincontext.size; + if ( *size != domctl.u.getdomaincontext.size ) + { + errno = EOVERFLOW; + return -1; + } + + return 0; +} + +int xc_domain_setcontext(xc_interface *xch, uint32_t domid, + const void *ctxt_buf, size_t size) +{ + int ret; + DECLARE_DOMCTL = { + .cmd = XEN_DOMCTL_setdomaincontext, + .domain = domid, + .u.setdomaincontext.size = size, + }; + DECLARE_HYPERCALL_BOUNCE_IN(ctxt_buf, size); + + if ( xc_hypercall_bounce_pre(xch, ctxt_buf) ) + return -1; + + set_xen_guest_handle(domctl.u.setdomaincontext.buffer, ctxt_buf); + + ret = do_domctl(xch, &domctl); + + xc_hypercall_bounce_post(xch, ctxt_buf); + + return ret; +} + int xc_vcpu_getcontext(xc_interface *xch, uint32_t domid, uint32_t vcpu, diff --git a/xen/common/domctl.c b/xen/common/domctl.c index a69b3b59a8..44758034a6 100644 --- a/xen/common/domctl.c +++ b/xen/common/domctl.c @@ -25,6 +25,8 @@ #include #include #include +#include +#include #include #include #include @@ -358,6 +360,168 @@ static struct vnuma_info *vnuma_init(const struct xen_domctl_vnuma *uinfo, return ERR_PTR(ret); } +struct domctl_context +{ + void *buffer; + struct domain_save_descriptor *desc; + size_t len; + size_t cur; +}; + +static int dry_run_append(void *priv, const void *data, size_t len) +{ + struct domctl_context *c = priv; + + if ( c->len + len < c->len ) + return -EOVERFLOW; + + c->len += len; + + return 0; +} + +static int dry_run_begin(void *priv, const struct domain_save_descriptor *desc) +{ + return dry_run_append(priv, NULL, sizeof(*desc)); +} + +static int dry_run_end(void *priv, size_t len) +{ + return 0; +} + +static struct domain_save_ops dry_run_ops = { + .begin = dry_run_begin, + .append = dry_run_append, + .end = dry_run_end, +}; + +static int save_begin(void *priv, const struct domain_save_descriptor *desc) +{ + struct domctl_context *c = priv; + + if ( c->len - c->cur < sizeof(*desc) ) + return -ENOSPC; + + c->desc = c->buffer + c->cur; /* stash pointer to descriptor */ + *c->desc = *desc; + + c->cur += sizeof(*desc); + + return 0; +} + +static int save_append(void *priv, const void *data, size_t len) +{ + struct domctl_context *c = priv; + + if ( c->len - c->cur < len ) + return -ENOSPC; + + memcpy(c->buffer + c->cur, data, len); + c->cur += len; + + return 0; +} + +static int save_end(void *priv, size_t len) +{ + struct domctl_context *c = priv; + + c->desc->length = len; + + return 0; +} + +static struct domain_save_ops save_ops = { + .begin = save_begin, + .append = save_append, + .end = save_end, +}; + +static int getdomaincontext(struct domain *d, + struct xen_domctl_getdomaincontext *gdc) +{ + struct domctl_context c = { .buffer = ZERO_BLOCK_PTR }; + int rc; + + if ( d == current->domain ) + return -EPERM; + + if ( gdc->pad ) + return -EINVAL; + + if ( guest_handle_is_null(gdc->buffer) ) /* query for buffer size */ + { + if ( gdc->size ) + return -EINVAL; + + /* dry run to acquire buffer size */ + rc = domain_save(d, &dry_run_ops, &c, true); + if ( rc ) + return rc; + + gdc->size = c.len; + return 0; + } + + c.len = gdc->size; + c.buffer = vmalloc(c.len); + if ( !c.buffer ) + return -ENOMEM; + + rc = domain_save(d, &save_ops, &c, false); + + gdc->size = c.cur; + if ( !rc && copy_to_guest(gdc->buffer, c.buffer, gdc->size) ) + rc = -EFAULT; + + vfree(c.buffer); + + return rc; +} + +static int load_read(void *priv, void *data, size_t len) +{ + struct domctl_context *c = priv; + + if ( c->len - c->cur < len ) + return -ENODATA; + + memcpy(data, c->buffer + c->cur, len); + c->cur += len; + + return 0; +} + +static struct domain_load_ops load_ops = { + .read = load_read, +}; + +static int setdomaincontext(struct domain *d, + const struct xen_domctl_setdomaincontext *sdc) +{ + struct domctl_context c = { .buffer = ZERO_BLOCK_PTR, .len = sdc->size }; + int rc; + + if ( d == current->domain ) + return -EPERM; + + if ( sdc->pad ) + return -EINVAL; + + c.buffer = vmalloc(c.len); + if ( !c.buffer ) + return -ENOMEM; + + rc = !copy_from_guest(c.buffer, sdc->buffer, c.len) ? + domain_load(d, &load_ops, &c) : -EFAULT; + + vfree(c.buffer); + + return rc; +} + long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl) { long ret = 0; @@ -942,6 +1106,15 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl) copyback = 1; break; + case XEN_DOMCTL_getdomaincontext: + ret = getdomaincontext(d, &op->u.getdomaincontext); + copyback = !ret; + break; + + case XEN_DOMCTL_setdomaincontext: + ret = setdomaincontext(d, &op->u.setdomaincontext); + break; + default: ret = arch_do_domctl(op, d, u_domctl); break; diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h index 1ad34c35eb..1b133bda59 100644 --- a/xen/include/public/domctl.h +++ b/xen/include/public/domctl.h @@ -1129,6 +1129,43 @@ struct xen_domctl_vuart_op { */ }; +/* + * XEN_DOMCTL_getdomaincontext + * --------------------------- + * + * buffer (IN): The buffer into which the context data should be + * copied, or NULL to query the buffer size that should + * be allocated. + * size (IN/OUT): If 'buffer' is NULL then the value passed in must be + * zero, and the value passed out will be the size of the + * buffer to allocate. + * If 'buffer' is non-NULL then the value passed in must + * be the size of the buffer into which data may be copied. + * The value passed out will be the size of data written. + */ +struct xen_domctl_getdomaincontext { + uint32_t size; + uint32_t pad; + XEN_GUEST_HANDLE_64(void) buffer; +}; + +/* XEN_DOMCTL_setdomaincontext + * --------------------------- + * + * buffer (IN): The buffer from which the context data should be + * copied. + * size (IN): The size of the buffer from which data may be copied. + * This data must include DOMAIN_SAVE_CODE_HEADER at the + * start and terminate with a DOMAIN_SAVE_CODE_END record. + * Any data beyond the DOMAIN_SAVE_CODE_END record will be + * ignored. + */ +struct xen_domctl_setdomaincontext { + uint32_t size; + uint32_t pad; + XEN_GUEST_HANDLE_64(const_void) buffer; +}; + struct xen_domctl { uint32_t cmd; #define XEN_DOMCTL_createdomain 1 @@ -1210,6 +1247,8 @@ struct xen_domctl { #define XEN_DOMCTL_vuart_op 81 #define XEN_DOMCTL_get_cpu_policy 82 #define XEN_DOMCTL_set_cpu_policy 83 +#define XEN_DOMCTL_getdomaincontext 84 +#define XEN_DOMCTL_setdomaincontext 85 #define XEN_DOMCTL_gdbsx_guestmemio 1000 #define XEN_DOMCTL_gdbsx_pausevcpu 1001 #define XEN_DOMCTL_gdbsx_unpausevcpu 1002 @@ -1270,6 +1309,8 @@ struct xen_domctl { struct xen_domctl_monitor_op monitor_op; struct xen_domctl_psr_alloc psr_alloc; struct xen_domctl_vuart_op vuart_op; + struct xen_domctl_getdomaincontext getdomaincontext; + struct xen_domctl_setdomaincontext setdomaincontext; uint8_t pad[128]; } u; }; diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c index 4649e6fd95..6f3db276ef 100644 --- a/xen/xsm/flask/hooks.c +++ b/xen/xsm/flask/hooks.c @@ -745,6 +745,12 @@ static int flask_domctl(struct domain *d, int cmd) case XEN_DOMCTL_get_cpu_policy: return current_has_perm(d, SECCLASS_DOMAIN2, DOMAIN2__GET_CPU_POLICY); + case XEN_DOMCTL_setdomaincontext: + return current_has_perm(d, SECCLASS_DOMAIN2, DOMAIN2__SETCONTEXT); + + case XEN_DOMCTL_getdomaincontext: + return current_has_perm(d, SECCLASS_DOMAIN2, DOMAIN2__GETCONTEXT); + default: return avc_unknown_permission("domctl", cmd); } diff --git a/xen/xsm/flask/policy/access_vectors b/xen/xsm/flask/policy/access_vectors index c055c14c26..fccfb9de82 100644 --- a/xen/xsm/flask/policy/access_vectors +++ b/xen/xsm/flask/policy/access_vectors @@ -245,6 +245,10 @@ class domain2 resource_map # XEN_DOMCTL_get_cpu_policy get_cpu_policy +# XEN_DOMCTL_setdomaincontext + setcontext +# XEN_DOMCTL_getdomaincontext + getcontext } # Similar to class domain, but primarily contains domctls related to HVM domains