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 DC4A9F419A5 for ; Wed, 15 Apr 2026 13:31:36 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wD0JO-0007Hk-0W; Wed, 15 Apr 2026 09:29:46 -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 1wD0JM-0007Fz-HH for qemu-devel@nongnu.org; Wed, 15 Apr 2026 09:29:44 -0400 Received: from pv-2002c-snip4-11.eps.apple.com ([57.103.64.241] helo=outbound.pv.icloud.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wD0JK-0004AE-Td for qemu-devel@nongnu.org; Wed, 15 Apr 2026 09:29:44 -0400 Received: from outbound.pv.icloud.com (unknown [127.0.0.2]) by p00-icloudmta-asmtp-us-west-1a-100-percent-11 (Postfix) with ESMTPS id C41AE18000AA; Wed, 15 Apr 2026 13:29:40 +0000 (UTC) X-ICL-Out-Info: HUtFAUMHWwJACUgDTUQeDx5WFlZNRAJCTQFIHV8DWRxBAUkdXw9LVxQEFVwFVgZXFHkNXR1FDlYZWgxSD1sOHBZLWFUJCgZdGFgVVgl3HlwASx1XBFQfUxJVHR0LRUtAEwRNEwVSB11NVg1HD1geXBQXCEVDXgheH0wcHQ5YBhIATQoONgZZBV4JVgNDBTYSFF1FRgNHGVcUUBtHDFUHV15fChMAXg8PTAtIAVsHXwNFCEsBVAVdHEUBQARVGlMfHVYQUgBSD3IFVwhBCFMCUQRYGl8IGQ1AThkMSh1SVlEFSgxcAGgPXR1YEV0= Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=unpredictable.fr; s=sig1; t=1776259781; x=1778851781; bh=NdNHW+HU7nWqdCiVuwZpuQ7yi7ZDV/6IOnp123UbLOQ=; h=From:To:Subject:Date:Message-ID:MIME-Version:x-icloud-hme; b=byWOFmWKdpFZwrPvNbXBODDs5cBqtb1G9Hc2K9ndjzl0v/45H8eaQluoCqu+jnkfi+QodT8/ZMCY8RlucepTQaAqJ1a/ZuybjYCcA9PBGovY1StiZhFR4+26IKbdVIm2rY0cJNFYEutTbw+RVZaK8sKu9CigBrxT3Wx2WxNoXEo0tse2O6Rwym9H4m6ymK4pawjvvmMvEcICdv8dvXpxRjNVsRkXFTEiv/p6FA71vYFZonBhzjbPE6BKh2gp0YqxF0957O9caQGNKvE9ELih9WhoRqNwp9IGMJHahsEI0NtyOvWvvZ3qBzf0x62k0yVCJUzvKlJyfk/W4tp9cwmh4g== mail-alias-created-date: 1752046281608 Received: from localhost.localdomain (unknown [17.56.9.36]) by p00-icloudmta-asmtp-us-west-1a-100-percent-11 (Postfix) with ESMTPSA id 721B3180034B; Wed, 15 Apr 2026 13:29:39 +0000 (UTC) From: Mohamed Mediouni To: qemu-devel@nongnu.org Cc: Mohamed Mediouni , Zhao Liu , Paolo Bonzini , Pedro Barbuda Subject: [PATCH v2 07/10] whpx: i386: add HV_X64_MSR_GUEST_IDLE when !kernel-irqchip Date: Wed, 15 Apr 2026 15:29:23 +0200 Message-ID: <20260415132926.58878-8-mohamed@unpredictable.fr> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20260415132926.58878-1-mohamed@unpredictable.fr> References: <20260415132926.58878-1-mohamed@unpredictable.fr> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Proofpoint-ORIG-GUID: FbdWsunsJBF2P3nOeWjcK73nI0VSS4Rq X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNDE1MDEyNSBTYWx0ZWRfX6CPToTixMAlv WNndKgmKL6BgyR40FIrwzEc7iWmmCtgourLXOLjBE/DHAX2GcMnzODwjjsb9DXOrcpV6MBI9YPC r1lEiemVRByGWchK00NudttFM0OF9MM/ewxriwi1ZLlC/ZRoJ3ThfrYIOdOsDaZ0m010u85enlQ o7N+bahrqHeMP9HOhe2T7GiuNPdZD7h77/Nd95Lb2DLvjxWmEjZCXdnghsXGf4htT6TfR/ii3Yx C+8UjwdAPqAQFVtGhbzSdBd1WjLrFxR5Nnmh0+EA7myNnAzQWlqZm9JTI47eFOTIQWQ7iBLyj73 ROxw3hPB0ez29u4AKVmq/2aHKpQjf9BWQ1cADa4XeaYuqH6haHnporkyV+ELi4= X-Authority-Info-Out: v=2.4 cv=Cu2ys34D c=1 sm=1 tr=0 ts=69df92c4 cx=c_apl:c_pps:t_out a=azHRBMxVc17uSn+fyuI/eg==:117 a=azHRBMxVc17uSn+fyuI/eg==:17 a=A5OVakUREuEA:10 a=VkNPw1HP01LnGYTKEx00:22 a=mSEN7FZ2dYRJNo9PPvgA:9 X-Proofpoint-GUID: FbdWsunsJBF2P3nOeWjcK73nI0VSS4Rq Received-SPF: pass client-ip=57.103.64.241; envelope-from=mohamed@unpredictable.fr; helo=outbound.pv.icloud.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, 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 Add support for an oddball HV_X64_MSR_GUEST_IDLE not-quite-an-HLT that wakes the vCPU even if EFLAGS.IF is set. Signed-off-by: Mohamed Mediouni --- target/i386/whpx/whpx-all.c | 46 ++++++++++++++++++++++++++++++++++--- 1 file changed, 43 insertions(+), 3 deletions(-) diff --git a/target/i386/whpx/whpx-all.c b/target/i386/whpx/whpx-all.c index 2e6679f40b..0b89fe093f 100644 --- a/target/i386/whpx/whpx-all.c +++ b/target/i386/whpx/whpx-all.c @@ -52,6 +52,7 @@ /* for kernel-irqchip=off */ #define HV_X64_MSR_APIC_FREQUENCY 0x40000023 #define HV_X64_MSR_VP_ASSIST_PAGE 0x40000073 +#define HV_X64_MSR_GUEST_IDLE 0x400000f0 static bool is_modern_os = true; @@ -1543,13 +1544,16 @@ static vaddr whpx_vcpu_get_pc(CPUState *cpu, bool exit_context_valid) } } -static int whpx_handle_halt(CPUState *cpu) +static int whpx_handle_halt_generic(CPUState *cpu) { + X86CPU *x86_cpu = X86_CPU(cpu); + CPUX86State *env = &x86_cpu->env; + int ret = 0; bql_lock(); if (!(cpu_test_interrupt(cpu, CPU_INTERRUPT_HARD) && - (cpu_env(cpu)->eflags & IF_MASK)) && + ((cpu_env(cpu)->eflags & IF_MASK) || env->hflags2 & HF2_HYPERV_HLT_MASK)) && !cpu_test_interrupt(cpu, CPU_INTERRUPT_NMI)) { cpu->exception_index = EXCP_HLT; cpu->halted = true; @@ -1560,6 +1564,27 @@ static int whpx_handle_halt(CPUState *cpu) return ret; } +static int whpx_handle_halt(CPUState *cpu) +{ + int ret = 0; + + ret = whpx_handle_halt_generic(cpu); + + return ret; +} + +static int whpx_handle_hyperv_guestidle(CPUState *cpu) +{ + X86CPU *x86_cpu = X86_CPU(cpu); + CPUX86State *env = &x86_cpu->env; + int ret = 0; + + env->hflags2 |= HF2_HYPERV_HLT_MASK; + ret = whpx_handle_halt_generic(cpu); + + return ret; +} + static void whpx_vcpu_kick_out_of_hlt(CPUState *cpu) { WHV_REGISTER_VALUE reg; @@ -1763,9 +1788,10 @@ static void whpx_vcpu_process_async_events(CPUState *cpu) } if ((cpu_test_interrupt(cpu, CPU_INTERRUPT_HARD) && - (env->eflags & IF_MASK)) || + ((env->eflags & IF_MASK) || env->hflags2 & HF2_HYPERV_HLT_MASK)) || cpu_test_interrupt(cpu, CPU_INTERRUPT_NMI)) { cpu->halted = false; + env->hflags2 &= ~HF2_HYPERV_HLT_MASK; } if (cpu_test_interrupt(cpu, CPU_INTERRUPT_SIPI)) { @@ -2035,6 +2061,20 @@ int whpx_vcpu_run(CPUState *cpu) } } + /* + * Windows and Linux both use this MSR. + * Windows 11 25H2 uses it even when not advertised. + */ + if (vcpu->exit_ctx.MsrAccess.MsrNumber == HV_X64_MSR_GUEST_IDLE + && !vcpu->exit_ctx.MsrAccess.AccessInfo.IsWrite + && !whpx_irqchip_in_kernel() + && whpx->hyperv_enlightenments_enabled) { + is_known_msr = 1; + whpx_bump_rip(cpu, &vcpu->exit_ctx); + ret = whpx_handle_hyperv_guestidle(cpu); + break; + } + /* * Linux tries to use it anyway even when not exposed. * Ignore the write as the VP assist page is not used. -- 2.50.1 (Apple Git-155)