From patchwork Wed May 27 17:34:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 11573639 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 64A32159A for ; Wed, 27 May 2020 17:36:14 +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 35DFD20707 for ; Wed, 27 May 2020 17:36:14 +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="iyZIATC7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 35DFD20707 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 1jdzwh-00033I-Lf; Wed, 27 May 2020 17:34:27 +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 4.92) (envelope-from ) id 1jdzwg-00032g-FB for xen-devel@lists.xenproject.org; Wed, 27 May 2020 17:34:26 +0000 X-Inumbo-ID: 4b99aecc-a040-11ea-a76e-12813bfff9fa Received: from mail.xenproject.org (unknown [104.130.215.37]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 4b99aecc-a040-11ea-a76e-12813bfff9fa; Wed, 27 May 2020 17:34:19 +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=6HfwJMUCo4w2pkMGpLCkcV69ZEzum7mNXZZZUP2qHUY=; b=iyZIATC7nbvbdFBWGH6A8Yz7IO 5zJ0+kkNhkDzn0oEQj44cuPo5WQ1HxIwdHX30e9I8JJOFrZR9qi/uwE0phYSfzLN71/EcFRq6Mckk 96mdJxxm5kUXomAcUklmwW98bACYwDc9k2nt45gNlpB3nj8jdthx6gFIy890Jde7kzpE=; Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jdzwZ-00016Y-4l; Wed, 27 May 2020 17:34:19 +0000 Received: from 54-240-197-224.amazon.com ([54.240.197.224] helo=u2f063a87eabd5f.cbg10.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jdzwY-0003od-SJ; Wed, 27 May 2020 17:34:19 +0000 From: Paul Durrant To: xen-devel@lists.xenproject.org Subject: [PATCH v6 5/5] tools/libxc: make use of domain context SHARED_INFO record... Date: Wed, 27 May 2020 18:34:07 +0100 Message-Id: <20200527173407.1398-6-paul@xen.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200527173407.1398-1-paul@xen.org> References: <20200527173407.1398-1-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: Andrew Cooper , Paul Durrant , Ian Jackson , Wei Liu , Paul Durrant Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" ... in the save/restore code. This patch replaces direct mapping of the shared_info_frame (retrieved using XEN_DOMCTL_getdomaininfo) with save/load of the domain context SHARED_INFO record. No modifications are made to the definition of the migration stream at this point. Subsequent patches will define a record in the libxc domain image format for passing domain context and convert the save/restore code to use that. Signed-off-by: Paul Durrant --- Cc: Andrew Cooper Cc: Ian Jackson Cc: Wei Liu NOTE: Ian requested ack from Andrew v5: - Added BUILD_BUG_ON() in write_shared_info() to ensure copied data is not bigger than the record buffer v4: - write_shared_info() now needs to allocate the record data since the shared info buffer is smaller than PAGE_SIZE v3: - Moved basic get/set domain context functions to common code v2: - Re-based (now making use of DOMAIN_SAVE_FLAG_IGNORE) --- tools/libxc/xc_sr_common.c | 67 +++++++++++++++++++++++++++ tools/libxc/xc_sr_common.h | 11 ++++- tools/libxc/xc_sr_common_x86_pv.c | 74 ++++++++++++++++++++++++++++++ tools/libxc/xc_sr_common_x86_pv.h | 3 ++ tools/libxc/xc_sr_restore_x86_pv.c | 26 ++++------- tools/libxc/xc_sr_save_x86_pv.c | 44 ++++++++---------- tools/libxc/xg_save_restore.h | 1 + 7 files changed, 182 insertions(+), 44 deletions(-) diff --git a/tools/libxc/xc_sr_common.c b/tools/libxc/xc_sr_common.c index dd9a11b4b5..1acb3765aa 100644 --- a/tools/libxc/xc_sr_common.c +++ b/tools/libxc/xc_sr_common.c @@ -138,6 +138,73 @@ int read_record(struct xc_sr_context *ctx, int fd, struct xc_sr_record *rec) return 0; }; +int get_domain_context(struct xc_sr_context *ctx) +{ + xc_interface *xch = ctx->xch; + size_t len = 0; + int rc; + + if ( ctx->domain_context.buffer ) + { + ERROR("Domain context already present"); + return -1; + } + + rc = xc_domain_getcontext(xch, ctx->domid, NULL, &len); + if ( rc < 0 ) + { + PERROR("Unable to get size of domain context"); + return -1; + } + + ctx->domain_context.buffer = malloc(len); + if ( !ctx->domain_context.buffer ) + { + PERROR("Unable to allocate memory for domain context"); + return -1; + } + + rc = xc_domain_getcontext(xch, ctx->domid, ctx->domain_context.buffer, + &len); + if ( rc < 0 ) + { + PERROR("Unable to get domain context"); + return -1; + } + + ctx->domain_context.len = len; + + return 0; +} + +int set_domain_context(struct xc_sr_context *ctx) +{ + xc_interface *xch = ctx->xch; + int rc; + + if ( !ctx->domain_context.buffer ) + { + ERROR("Domain context not present"); + return -1; + } + + rc = xc_domain_setcontext(xch, ctx->domid, ctx->domain_context.buffer, + ctx->domain_context.len); + + if ( rc < 0 ) + { + PERROR("Unable to set domain context"); + return -1; + } + + return 0; +} + +void common_cleanup(struct xc_sr_context *ctx) +{ + free(ctx->domain_context.buffer); +} + static void __attribute__((unused)) build_assertions(void) { BUILD_BUG_ON(sizeof(struct xc_sr_ihdr) != 24); diff --git a/tools/libxc/xc_sr_common.h b/tools/libxc/xc_sr_common.h index 5dd51ccb15..0d61978b08 100644 --- a/tools/libxc/xc_sr_common.h +++ b/tools/libxc/xc_sr_common.h @@ -208,6 +208,11 @@ struct xc_sr_context xc_dominfo_t dominfo; + struct { + void *buffer; + unsigned int len; + } domain_context; + union /* Common save or restore data. */ { struct /* Save data. */ @@ -314,7 +319,7 @@ struct xc_sr_context /* The guest pfns containing the p2m leaves */ xen_pfn_t *p2m_pfns; - /* Read-only mapping of guests shared info page */ + /* Pointer to shared_info (located in context buffer) */ shared_info_any_t *shinfo; /* p2m generation count for verifying validity of local p2m. */ @@ -425,6 +430,10 @@ int read_record(struct xc_sr_context *ctx, int fd, struct xc_sr_record *rec); int populate_pfns(struct xc_sr_context *ctx, unsigned int count, const xen_pfn_t *original_pfns, const uint32_t *types); +int get_domain_context(struct xc_sr_context *ctx); +int set_domain_context(struct xc_sr_context *ctx); +void common_cleanup(struct xc_sr_context *ctx); + #endif /* * Local variables: diff --git a/tools/libxc/xc_sr_common_x86_pv.c b/tools/libxc/xc_sr_common_x86_pv.c index d3d425cb82..69d9b142b8 100644 --- a/tools/libxc/xc_sr_common_x86_pv.c +++ b/tools/libxc/xc_sr_common_x86_pv.c @@ -182,6 +182,80 @@ int x86_pv_map_m2p(struct xc_sr_context *ctx) return rc; } +int x86_pv_get_shinfo(struct xc_sr_context *ctx) +{ + xc_interface *xch = ctx->xch; + unsigned int off = 0; + int rc; + +#define GET_PTR(_x) \ + do { \ + if ( ctx->domain_context.len - off < sizeof(*(_x)) ) \ + { \ + ERROR("Need another %lu bytes of context, only %u available\n", \ + sizeof(*(_x)), ctx->domain_context.len - off); \ + return -1; \ + } \ + (_x) = ctx->domain_context.buffer + off; \ + } while (false); + + rc = get_domain_context(ctx); + if ( rc ) + return rc; + + for ( ; ; ) + { + struct domain_save_descriptor *desc; + + GET_PTR(desc); + + off += sizeof(*desc); + + switch (desc->typecode) + { + case DOMAIN_SAVE_CODE(SHARED_INFO): + { + DOMAIN_SAVE_TYPE(SHARED_INFO) *s; + + GET_PTR(s); + + ctx->x86.pv.shinfo = (shared_info_any_t *)s->buffer; + break; + } + default: + break; + } + + if ( desc->typecode == DOMAIN_SAVE_CODE(END) ) + break; + + off += desc->length; + } + + if ( !ctx->x86.pv.shinfo ) + { + ERROR("Failed to get SHARED_INFO\n"); + return -1; + } + + return 0; + +#undef GET_PTR +} + +int x86_pv_set_shinfo(struct xc_sr_context *ctx) +{ + xc_interface *xch = ctx->xch; + + if ( !ctx->x86.pv.shinfo ) + { + ERROR("SHARED_INFO buffer not present\n"); + return -1; + } + + return set_domain_context(ctx); +} + /* * Local variables: * mode: C diff --git a/tools/libxc/xc_sr_common_x86_pv.h b/tools/libxc/xc_sr_common_x86_pv.h index 2ed03309af..01442f48fb 100644 --- a/tools/libxc/xc_sr_common_x86_pv.h +++ b/tools/libxc/xc_sr_common_x86_pv.h @@ -97,6 +97,9 @@ int x86_pv_domain_info(struct xc_sr_context *ctx); */ int x86_pv_map_m2p(struct xc_sr_context *ctx); +int x86_pv_get_shinfo(struct xc_sr_context *ctx); +int x86_pv_set_shinfo(struct xc_sr_context *ctx); + #endif /* * Local variables: diff --git a/tools/libxc/xc_sr_restore_x86_pv.c b/tools/libxc/xc_sr_restore_x86_pv.c index 904ccc462a..21982a38ad 100644 --- a/tools/libxc/xc_sr_restore_x86_pv.c +++ b/tools/libxc/xc_sr_restore_x86_pv.c @@ -865,7 +865,7 @@ static int handle_shared_info(struct xc_sr_context *ctx, xc_interface *xch = ctx->xch; unsigned int i; int rc = -1; - shared_info_any_t *guest_shinfo = NULL; + shared_info_any_t *guest_shinfo; const shared_info_any_t *old_shinfo = rec->data; if ( !ctx->x86.pv.restore.seen_pv_info ) @@ -878,18 +878,14 @@ static int handle_shared_info(struct xc_sr_context *ctx, { ERROR("X86_PV_SHARED_INFO record wrong size: length %u" ", expected 4096", rec->length); - goto err; + return -1; } - guest_shinfo = xc_map_foreign_range( - xch, ctx->domid, PAGE_SIZE, PROT_READ | PROT_WRITE, - ctx->dominfo.shared_info_frame); - if ( !guest_shinfo ) - { - PERROR("Failed to map Shared Info at mfn %#lx", - ctx->dominfo.shared_info_frame); - goto err; - } + rc = x86_pv_get_shinfo(ctx); + if ( rc ) + return rc; + + guest_shinfo = ctx->x86.pv.shinfo; MEMCPY_FIELD(guest_shinfo, old_shinfo, vcpu_info, ctx->x86.pv.width); MEMCPY_FIELD(guest_shinfo, old_shinfo, arch, ctx->x86.pv.width); @@ -904,13 +900,7 @@ static int handle_shared_info(struct xc_sr_context *ctx, MEMSET_ARRAY_FIELD(guest_shinfo, evtchn_mask, 0xff, ctx->x86.pv.width); - rc = 0; - - err: - if ( guest_shinfo ) - munmap(guest_shinfo, PAGE_SIZE); - - return rc; + return x86_pv_set_shinfo(ctx); } /* restore_ops function. */ diff --git a/tools/libxc/xc_sr_save_x86_pv.c b/tools/libxc/xc_sr_save_x86_pv.c index f3ccf5bb4b..fdd172b639 100644 --- a/tools/libxc/xc_sr_save_x86_pv.c +++ b/tools/libxc/xc_sr_save_x86_pv.c @@ -9,25 +9,6 @@ static inline bool is_canonical_address(xen_vaddr_t vaddr) return ((int64_t)vaddr >> 47) == ((int64_t)vaddr >> 63); } -/* - * Maps the guests shared info page. - */ -static int map_shinfo(struct xc_sr_context *ctx) -{ - xc_interface *xch = ctx->xch; - - ctx->x86.pv.shinfo = xc_map_foreign_range( - xch, ctx->domid, PAGE_SIZE, PROT_READ, ctx->dominfo.shared_info_frame); - if ( !ctx->x86.pv.shinfo ) - { - PERROR("Failed to map shared info frame at mfn %#lx", - ctx->dominfo.shared_info_frame); - return -1; - } - - return 0; -} - /* * Copy a list of mfns from a guest, accounting for differences between guest * and toolstack width. Can fail if truncation would occur. @@ -854,13 +835,27 @@ static int write_x86_pv_p2m_frames(struct xc_sr_context *ctx) */ static int write_shared_info(struct xc_sr_context *ctx) { + xc_interface *xch = ctx->xch; struct xc_sr_record rec = { .type = REC_TYPE_SHARED_INFO, .length = PAGE_SIZE, - .data = ctx->x86.pv.shinfo, }; + int rc; - return write_record(ctx, &rec); + if ( !(rec.data = calloc(1, PAGE_SIZE)) ) + { + ERROR("Cannot allocate buffer for SHARED_INFO data"); + return -1; + } + + BUILD_BUG_ON(sizeof(*ctx->x86.pv.shinfo) > PAGE_SIZE); + memcpy(rec.data, ctx->x86.pv.shinfo, sizeof(*ctx->x86.pv.shinfo)); + + rc = write_record(ctx, &rec); + + free(rec.data); + + return rc; } /* @@ -1041,7 +1036,7 @@ static int x86_pv_setup(struct xc_sr_context *ctx) if ( rc ) return rc; - rc = map_shinfo(ctx); + rc = x86_pv_get_shinfo(ctx); if ( rc ) return rc; @@ -1112,12 +1107,11 @@ static int x86_pv_cleanup(struct xc_sr_context *ctx) if ( ctx->x86.pv.p2m ) munmap(ctx->x86.pv.p2m, ctx->x86.pv.p2m_frames * PAGE_SIZE); - if ( ctx->x86.pv.shinfo ) - munmap(ctx->x86.pv.shinfo, PAGE_SIZE); - if ( ctx->x86.pv.m2p ) munmap(ctx->x86.pv.m2p, ctx->x86.pv.nr_m2p_frames * PAGE_SIZE); + common_cleanup(ctx); + return 0; } diff --git a/tools/libxc/xg_save_restore.h b/tools/libxc/xg_save_restore.h index 303081df0d..296b523963 100644 --- a/tools/libxc/xg_save_restore.h +++ b/tools/libxc/xg_save_restore.h @@ -19,6 +19,7 @@ #include #include +#include /* ** We process save/restore/migrate in batches of pages; the below