From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D6BBE179A3; Fri, 29 Aug 2025 00:03:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756425814; cv=none; b=YTBj0yqhbVA+ubrrf6ULi7Iugfb/zc07Vb5ecJcpQSMwmfeQFVVzD2SV+JgFp7y0rfqk5I1zyuwh0JuAHSppaYFOwhtXo2VG5DjflXvelxaKcSrx3jOh+eIJy+stKA1jWO6KUh2rrKhNz2Dz4nEaEDFG/cYJyA5tQgR2AIT2UPU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756425814; c=relaxed/simple; bh=h9ECKGOoE8l6lXBXfI/nqr/yvcdfmjjurJiByFbfZ+g=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hxBnOUAOqJVRqK8WUpAb6X83ZGXxxFdmPoPs0eB30AwCuJFlcFClPLyuZyw3zJhLxmu3UTklnxyINB5mFN2x27+BIsgOoQbfjgGLHJD1mzHoj3Dg6k/ydyisxQ0CNngI4TpaFBeDciR9zG9dKWLcPcOZXtG9EYKLn+mMraICO2Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=b/Cp3YVn; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="b/Cp3YVn" Received: from [100.65.128.219] (unknown [20.236.11.69]) by linux.microsoft.com (Postfix) with ESMTPSA id 29236211080D; Thu, 28 Aug 2025 17:03:30 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 29236211080D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1756425810; bh=NHYELJgOgtoYXMJjyiZ6Y/1BY77k4JUs4dbKzcllNgc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=b/Cp3YVnPly7ZmtMQDa2AEMRoQa4CxzO0/V6ejotdr50lR5itAta36gVWEjEJkADW rU7s8pjJhzWn/fR2q78z1pzSDm8R5EbcWLUxToRvAEbLWCrmz4XX39aTX/yCwcbIg0 s7ITLAqpkbVOXbI9g+AL0NaazVp0H0AaluYJk0kI= Message-ID: Date: Thu, 28 Aug 2025 17:03:28 -0700 Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 6/7] Drivers: hv: Use common "entry virt" APIs to do work in root before running guest To: Sean Christopherson , Marc Zyngier , Oliver Upton , Catalin Marinas , Will Deacon , Tianrui Zhao , Bibo Mao , Huacai Chen , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Peter Zijlstra , Andy Lutomirski , "Paul E. McKenney" , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Uladzislau Rezki Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, loongarch@lists.linux.dev, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-hyperv@vger.kernel.org, rcu@vger.kernel.org, Mukesh R References: <20250828000156.23389-1-seanjc@google.com> <20250828000156.23389-7-seanjc@google.com> Content-Language: en-US From: Nuno Das Neves In-Reply-To: <20250828000156.23389-7-seanjc@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/27/2025 5:01 PM, Sean Christopherson wrote: > Use the kernel's common "entry virt" APIs to handle pending work prior to > (re)entering guest mode, now that the virt APIs don't have a superfluous > dependency on KVM. > > No functional change intended. > > Signed-off-by: Sean Christopherson > --- > drivers/hv/Kconfig | 1 + > drivers/hv/mshv_root_main.c | 32 ++++++-------------------------- > 2 files changed, 7 insertions(+), 26 deletions(-) > > diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig > index 2e8df09db599..894037afcbf9 100644 > --- a/drivers/hv/Kconfig > +++ b/drivers/hv/Kconfig > @@ -66,6 +66,7 @@ config MSHV_ROOT > # no particular order, making it impossible to reassemble larger pages > depends on PAGE_SIZE_4KB > select EVENTFD > + select VIRT_XFER_TO_GUEST_WORK > default n > help > Select this option to enable support for booting and running as root > diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c > index 0d849f09160a..7c83f656e071 100644 > --- a/drivers/hv/mshv_root_main.c > +++ b/drivers/hv/mshv_root_main.c > @@ -8,6 +8,7 @@ > * Authors: Microsoft Linux virtualization team > */ > > +#include > #include > #include > #include > @@ -481,29 +482,6 @@ mshv_vp_wait_for_hv_kick(struct mshv_vp *vp) > return 0; > } > > -static int mshv_pre_guest_mode_work(struct mshv_vp *vp) > -{ > - const ulong work_flags = _TIF_NOTIFY_SIGNAL | _TIF_SIGPENDING | > - _TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY | > - _TIF_NOTIFY_RESUME; > - ulong th_flags; > - > - th_flags = read_thread_flags(); > - while (th_flags & work_flags) { > - int ret; > - > - /* nb: following will call schedule */ > - ret = mshv_do_pre_guest_mode_work(th_flags); > - > - if (ret) > - return ret; > - > - th_flags = read_thread_flags(); > - } > - > - return 0; > -} > - > /* Must be called with interrupts enabled */ > static long mshv_run_vp_with_root_scheduler(struct mshv_vp *vp) > { > @@ -524,9 +502,11 @@ static long mshv_run_vp_with_root_scheduler(struct mshv_vp *vp) > u32 flags = 0; > struct hv_output_dispatch_vp output; > > - ret = mshv_pre_guest_mode_work(vp); > - if (ret) > - break; > + if (__xfer_to_guest_mode_work_pending()) { > + ret = xfer_to_guest_mode_handle_work(); > + if (ret) > + break; > + } > > if (vp->run.flags.intercept_suspend) > flags |= HV_DISPATCH_VP_FLAG_CLEAR_INTERCEPT_SUSPEND; Also tested mshv_root with 1-6 applied, looks good to me. Possibly Naman, Saurabh, or Roman can test the mshv_vtl patches, I can't do it unfortunately. Tested-by: Nuno Das Neves Reviewed-by: Nuno Das Neves