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 Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 88C24C79F99 for ; Mon, 7 Sep 2026 14:24:53 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1x3aGU-0004Wj-Bd; Mon, 07 Sep 2026 10:24:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1x3aGT-0004WW-A9 for qemu-devel@nongnu.org; Mon, 07 Sep 2026 10:24:05 -0400 Received: from linux.microsoft.com ([13.77.154.182]) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1x3aGR-0006Ye-EN for qemu-devel@nongnu.org; Mon, 07 Sep 2026 10:24:05 -0400 Received: from laptop.localdomain (unknown [81.196.141.93]) by linux.microsoft.com (Postfix) with ESMTPSA id 6F58520B712B; Mon, 7 Sep 2026 07:23:21 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 6F58520B712B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1788791003; bh=J1brsl71IEXD02jTIvt6amMa7SMls9Qs5ZHUMqIyFqM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pvJX2ZR1Np77wT+geR7t5dQDL+qN++dcT94Zfec8yzWS3aPB96GP12mCYxj5R2F1C Cny9/BzKPhCsYiiraKl2e5IQzfoUdyySsNEnbOYuK4Z9pN70Qw1Q3zi1peEUDrwt7L hSDCblPnrx/YdcICX1N8oTMO7zBdNqH6lHFCALd4= From: =?UTF-8?q?Doru=20Bl=C3=A2nzeanu?= To: qemu-devel@nongnu.org Cc: Wei Liu , Magnus Kulke , Wei Liu , Magnus Kulke , =?UTF-8?q?Doru=20Bl=C3=A2nzeanu?= , =?UTF-8?q?Doru=20Bl=C3=A2nzeanu?= Subject: [PATCH 1/2] accel/mshv: size XSAVE buffers from the hypervisor Date: Mon, 7 Sep 2026 17:23:54 +0300 Message-ID: <20260907142355.141033-2-dblanzeanu@linux.microsoft.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260907142355.141033-1-dblanzeanu@linux.microsoft.com> References: <20260907142355.141033-1-dblanzeanu@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=13.77.154.182; envelope-from=dblanzeanu@linux.microsoft.com; helo=linux.microsoft.com X-Spam_score_int: -19 X-Spam_score: -2.0 X-Spam_bar: -- X-Spam_report: (-2.0 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Query MAX_XSAVE_DATA_SIZE at vcpu creation and cache it in MshvState. Introduce a new trace event for the xsave area size reported by the hypervisor. Also fixes a leak of xsavec_buf on the get error path and switches qemu_memalign() buffers to qemu_vfree(). No functional change on hosts reporting under 4 KiB. Signed-off-by: Doru Blânzeanu --- accel/mshv/mshv-all.c | 21 +++++++++++++++++++++ accel/mshv/trace-events | 2 ++ include/system/mshv_int.h | 3 +++ target/i386/mshv/mshv-cpu.c | 34 +++++++++++++++++++++++++--------- 4 files changed, 51 insertions(+), 9 deletions(-) diff --git a/accel/mshv/mshv-all.c b/accel/mshv/mshv-all.c index 5921ce693e..725ccd0511 100644 --- a/accel/mshv/mshv-all.c +++ b/accel/mshv/mshv-all.c @@ -162,6 +162,27 @@ static int get_proc_features(int vm_fd, return 0; } +int mshv_get_max_xsave_size(int vm_fd, uint32_t *size) +{ + uint64_t value = 0; + int ret; + + ret = get_partition_property(vm_fd, + HV_PARTITION_PROPERTY_MAX_XSAVE_DATA_SIZE, + &value); + if (ret < 0) { + error_report("Failed to get partition property MAX_XSAVE_DATA_SIZE"); + return -1; + } + + /* round up to page size */ + *size = ROUND_UP(value, HV_HYP_PAGE_SIZE); + + trace_mshv_xsave_data_size(value, *size); + + return 0; +} + static int create_partition(int mshv_fd, int *vm_fd) { int ret; diff --git a/accel/mshv/trace-events b/accel/mshv/trace-events index 859e8bfb0f..9473530140 100644 --- a/accel/mshv/trace-events +++ b/accel/mshv/trace-events @@ -12,6 +12,8 @@ mshv_mem_ioeventfd_del(uint64_t addr, uint32_t size, uint32_t data) "addr=0x%" P mshv_hvcall_args(const char* hvcall, uint16_t code, uint16_t in_sz) "built args for '%s' code: %d in_sz: %d" +mshv_xsave_data_size(uint64_t required, uint32_t allocated) "required=%" PRIu64 " allocated=%u" + mshv_handle_interrupt(uint32_t cpu, int mask) "cpu_index=%d mask=0x%x" mshv_set_msi_routing(uint32_t gsi, uint64_t addr, uint32_t data) "gsi=%d addr=0x%" PRIx64 " data=0x%x" mshv_remove_msi_routing(uint32_t gsi) "gsi=%d" diff --git a/include/system/mshv_int.h b/include/system/mshv_int.h index 3dffe3c5fb..9d0957a65b 100644 --- a/include/system/mshv_int.h +++ b/include/system/mshv_int.h @@ -70,6 +70,8 @@ struct MshvState { unsigned long *used_gsi_bitmap; unsigned int gsi_count; union hv_partition_processor_features processor_features; + /* compacted xsave area size rounded up to the page size */ + uint32_t xsave_data_size; }; typedef struct MshvMsiControl { @@ -107,6 +109,7 @@ void mshv_arch_amend_proc_features( void mshv_arch_disable_partition_proc_features( union hv_partition_processor_features *disabled_features); int mshv_arch_post_init_vm(int vm_fd); +int mshv_get_max_xsave_size(int vm_fd, uint32_t *size); int mshv_get_vp_state(int cpu_fd, struct mshv_get_set_vp_state *state); int mshv_set_vp_state(int cpu_fd, const struct mshv_get_set_vp_state *state); typedef struct mshv_root_hvcall mshv_root_hvcall; diff --git a/target/i386/mshv/mshv-cpu.c b/target/i386/mshv/mshv-cpu.c index f528dd2b9a..7ce05bfb17 100644 --- a/target/i386/mshv/mshv-cpu.c +++ b/target/i386/mshv/mshv-cpu.c @@ -157,9 +157,8 @@ static int get_xsave_state(CPUState *cpu) int ret; void *xsavec_buf; const size_t page = HV_HYP_PAGE_SIZE; - size_t xsavec_buf_len = page; + size_t xsavec_buf_len = mshv_state->xsave_data_size; - /* TODO: should properly determine xsavec size based on CPUID */ xsavec_buf = qemu_memalign(page, xsavec_buf_len); memset(xsavec_buf, 0, xsavec_buf_len); @@ -172,11 +171,12 @@ static int get_xsave_state(CPUState *cpu) ret = ioctl(cpu_fd, MSHV_GET_VP_STATE, &args); if (ret < 0) { error_report("failed to get xsave state: %s", strerror(errno)); + qemu_vfree(xsavec_buf); return -errno; } ret = decompact_xsave_area(xsavec_buf, xsavec_buf_len, env); - g_free(xsavec_buf); + qemu_vfree(xsavec_buf); if (ret < 0) { error_report("failed to decompact xsave area"); return ret; @@ -196,8 +196,8 @@ static int set_xsave_state(const CPUState *cpu) size_t page = HV_HYP_PAGE_SIZE, xsavec_buf_len; /* allocate and populate compacted buffer */ - xsavec_buf = qemu_memalign(page, page); - xsavec_buf_len = page; + xsavec_buf_len = mshv_state->xsave_data_size; + xsavec_buf = qemu_memalign(page, xsavec_buf_len); /* save registers to standard format buffer */ x86_cpu_xsave_all_areas(x86cpu, env->xsave_buf, env->xsave_buf_len); @@ -212,7 +212,7 @@ static int set_xsave_state(const CPUState *cpu) }; ret = ioctl(cpu_fd, MSHV_SET_VP_STATE, &args); - g_free(xsavec_buf); + qemu_vfree(xsavec_buf); if (ret < 0) { error_report("failed to set xsave state: %s", strerror(errno)); return -errno; @@ -2125,6 +2125,24 @@ void mshv_arch_init_vcpu(CPUState *cpu) int ret; X86XSaveHeader *header; + /* get the xsave data size */ + if (!mshv_state->xsave_data_size) { + ret = mshv_get_max_xsave_size(mshv_state->vm, + &mshv_state->xsave_data_size); + if (ret < 0) { + warn_report("failed to get the max xsave area size: %s", + strerror(errno)); + /* + * Use the maximum size for xsave because the partition is + * provisioned with every XSAVE component supported + */ + mshv_state->xsave_data_size = + ROUND_UP(mshv_get_supported_cpuid(0xD, 0, R_ECX), page); + } + /* never allow a zero-sized xsave area */ + mshv_state->xsave_data_size = MAX(mshv_state->xsave_data_size, page); + } + /* sanity check, to make sure we don't overflow the page */ QEMU_BUILD_BUG_ON((MAX_REGISTER_COUNT * sizeof(hv_register_assoc) @@ -2149,9 +2167,7 @@ void mshv_arch_init_vcpu(CPUState *cpu) env->emu_mmio_buf = g_new(char, 4096); - /* Initialize XSAVE buffer page-aligned */ - /* TODO: pick proper size based on CPUID */ - xsave_len = page; + xsave_len = mshv_state->xsave_data_size; env->xsave_buf = qemu_memalign(page, xsave_len); env->xsave_buf_len = xsave_len; memset(env->xsave_buf, 0, env->xsave_buf_len); -- 2.53.0