From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A6D371EE7B7 for ; Fri, 5 Sep 2025 05:39:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757050787; cv=none; b=iH44UChGJJxzUf2/5cX2dNUEEzhFhIYNUIvPBfUeAkNEuaUbyk+vcw3bUjuhT/Hi+7EgJBxAfhlv5I/4lKU3+FtYTv5uOkvmlF1NkRDEBcV0GVQgdX1WO2JcavXpB1mA+QVeLNifKlNQJW8S52335zHW85OnQTeYs7xOj1xHOD8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757050787; c=relaxed/simple; bh=wP0Nh39SvLrrUzcjoVyfrVPxYIzy1SY/V7/2kWcMIHU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=syfz38fyMxFnv8ispU9TFzADUr5x5QPLdmpbJylR3kpbiVYYgaYuwl//2F0ZxUCZ4z5FXaBmBPpUrqcrUuwXCdIcgB0IgfqwIY+z/0OuCn1HFhl4ceQby3mxWMIM4/FR7mtQEJcXc5IVTh7fuc/LWBvjkDFoGmznIM0LHGehs0Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=lQwzYtm2; arc=none smtp.client-ip=209.85.216.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="lQwzYtm2" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-32b698861d8so1810646a91.2 for ; Thu, 04 Sep 2025 22:39:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1757050785; x=1757655585; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=3udnh9xsllR+FkjIGPPOo5bX8r6scLid4vmBPD5wmTc=; b=lQwzYtm2NV4Io4r/i3BCtkCOVhcIr4Ap4aY1jaLJulrXaLdfg75M9pjFwojB5+NfTR yHNRD18Y2qWcloAz3pRVhvfcE1ozVRkyC4xMA5+5XuqA3HgIOgoAZRLlWS5Ar0NFszU2 OZ6iyQ1zLlPxMtI7rbEhXVGLS65b9oBWuz2O2LPIJQnIddCHaMwaA2q3X5/wVYuPCV4A ltJ6N26FjQ5ruch2n5EzaV7VzoWAeO0rn+jMgaJhMYg0zGD/lnaNlFwReK6FUlwFh67/ VIMIFskP0SM4Yl9o+nH4nt9Ysq/iV1lH3rr4bl8GwXz8DWXh+4346twU30d/LpBESjku 9DOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757050785; x=1757655585; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=3udnh9xsllR+FkjIGPPOo5bX8r6scLid4vmBPD5wmTc=; b=Zqum8cNpYFqcDagKgdvfO++6rWT7tk9dxx2zEu00A4MzutNMt5WoqKm1E4Xmh6yBol iQ0RPciX0Z3/fdCCuxfDAC/YhBBzPduUXx7s4Zs1OxTS2hesBpBiCXDJ7darLZLyGsiX 3JRv5aWAabqCkHPS17EU/yAnJNBISVa0mZw7aGh8+a+tx4EkQNuQcxdiUDXU5uwg0oLz 0pxpp/k+CZ5C1GiCtecAd/r1OYvJaPeh1yLYs7PJdQ8I9esjAExruCy5eQO2/7gd1d2g MKWl4M/7bDTnG1CYHpbjfMTH/bQQWmQLxazkUTDUj3vqKgEt9bHKnqCGBNxSGqUdHdPa nKDg== X-Forwarded-Encrypted: i=1; AJvYcCV4TtYUs2LLzxdmxD/eamB+XoszlLN8xv8mcPTJufVM9sHXf8Brat8F5FI9Fi6coLUgbNzG9jXnrZu7m30=@vger.kernel.org X-Gm-Message-State: AOJu0Yxl/c/g9oIHXGtkaLMB4DUJy4JhNS5djEMyrBDRo7lL16sE24e1 uz+CZ4RVREtnB6AjeTLAeRYMawx1tFKzud0zvJylC+c8jagyu9KnkZ/ZtMXZ6fz/6ZYiWp7oTxg E+xfzAg== X-Google-Smtp-Source: AGHT+IEl3aDxdJxOeFOgsIqqYfLRUExl039yXm0dtHzzby5zYzVGU35ZbpW1dVjZIdU0C50mCLd9IUYMCJw= X-Received: from pjuw15.prod.google.com ([2002:a17:90a:d60f:b0:325:5e4e:4bd4]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:3809:b0:329:dff0:701b with SMTP id 98e67ed59e1d1-329dff070c6mr19066965a91.17.1757050784899; Thu, 04 Sep 2025 22:39:44 -0700 (PDT) Date: Thu, 4 Sep 2025 22:39:37 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250828000156.23389-1-seanjc@google.com> Message-ID: Subject: Re: [PATCH v2 0/7] Drivers: hv: Fix NEED_RESCHED_LAZY and use common APIs From: Sean Christopherson To: Wei Liu Cc: 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 , Dexuan Cui , Peter Zijlstra , Andy Lutomirski , "Paul E. McKenney" , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Uladzislau Rezki , 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, Nuno Das Neves , Mukesh R Content-Type: text/plain; charset="us-ascii" On Thu, Sep 04, 2025, Wei Liu wrote: > On Wed, Aug 27, 2025 at 05:01:49PM -0700, Sean Christopherson wrote: > > Fix a bug where MSHV root partitions (and upper-level VTL code) don't honor > > NEED_RESCHED_LAZY, and then deduplicate the TIF related MSHV code by turning > > the "kvm" entry APIs into more generic "virt" APIs. > > > > This version is based on > > > > git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git hyperv-next > > > > in order to pickup the VTL changes that are queued for 6.18. I also > > squashed the NEED_RESCHED_LAZY fixes for root and VTL modes into a single > > patch, as it should be easy/straightforward to drop the VTL change as needed > > if we want this in 6.17 or earlier. > > > > That effectively means the full series is dependent on the VTL changes being > > fully merged for 6.18. But I think that's ok as it's really only the MSHV > > changes that have any urgency whatsoever, and I assume that Microsoft is > > the only user that truly cares about the MSHV root fix. I.e. if the whole > > thing gets delayed, I think it's only the Hyper-V folks that are impacted. > > > > I have no preference what tree this goes through, or when, and can respin > > and/or split as needed. > > > > As with v1, the Hyper-V stuff and non-x86 architectures are compile-tested > > only. > > > > v2: > > - Rebase on hyperv-next. > > - Fix and converge the VTL code as well. [Peter, Nuno] > > > > v1: https://lore.kernel.org/all/20250825200622.3759571-1-seanjc@google.com > > > > I dropped the mshv_vtl changes in this series and applied the rest > (including the KVM changes) to hyperv-next. mshv_do_pre_guest_mode_work() ended up getting left behind since its removal was in the last mshv_vtl patch. $ git grep mshv_do_pre_guest_mode_work drivers/hv/mshv.h:int mshv_do_pre_guest_mode_work(ulong th_flags); drivers/hv/mshv_common.c:int mshv_do_pre_guest_mode_work(ulong th_flags) drivers/hv/mshv_common.c:EXPORT_SYMBOL_GPL(mshv_do_pre_guest_mode_work); Want to squash this into 3786d7d6b3c0 ("mshv: Use common "entry virt" APIs to do work in root before running guest")? --- drivers/hv/mshv.h | 2 -- drivers/hv/mshv_common.c | 22 ---------------------- 2 files changed, 24 deletions(-) diff --git a/drivers/hv/mshv.h b/drivers/hv/mshv.h index 0340a67acd0a..d4813df92b9c 100644 --- a/drivers/hv/mshv.h +++ b/drivers/hv/mshv.h @@ -25,6 +25,4 @@ int hv_call_set_vp_registers(u32 vp_index, u64 partition_id, u16 count, int hv_call_get_partition_property(u64 partition_id, u64 property_code, u64 *property_value); -int mshv_do_pre_guest_mode_work(ulong th_flags); - #endif /* _MSHV_H */ diff --git a/drivers/hv/mshv_common.c b/drivers/hv/mshv_common.c index eb3df3e296bb..aa2be51979fd 100644 --- a/drivers/hv/mshv_common.c +++ b/drivers/hv/mshv_common.c @@ -138,25 +138,3 @@ int hv_call_get_partition_property(u64 partition_id, return 0; } EXPORT_SYMBOL_GPL(hv_call_get_partition_property); - -/* - * Handle any pre-processing before going into the guest mode on this cpu, most - * notably call schedule(). Must be invoked with both preemption and - * interrupts enabled. - * - * Returns: 0 on success, -errno on error. - */ -int mshv_do_pre_guest_mode_work(ulong th_flags) -{ - if (th_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) - return -EINTR; - - if (th_flags & (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY)) - schedule(); - - if (th_flags & _TIF_NOTIFY_RESUME) - resume_user_mode_work(NULL); - - return 0; -} -EXPORT_SYMBOL_GPL(mshv_do_pre_guest_mode_work); base-commit: 3786d7d6b3c0a412ebe4439ba4a7d4b0e27d9a12 --