From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 2628C86347 for ; Thu, 28 Aug 2025 00:02:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756339328; cv=none; b=GzuPJGfW5DtiGH2a5MdW43x4YQ7Z4wiH6XkAw+IRVF7YrWlvCEwUZ4Ynzf+909HB+68aHDagaLbTz9bwRSi6DQbwdBO8h1qsGSQjp482fEi3IDwH8xieMowq0+Z67tJrP9/Jp0gqxBOORdUAemjoGVihZgieSaW/3NH4sgWZprw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756339328; c=relaxed/simple; bh=8tZ83PeYs29SmFwlLYawA90+tGBTxdUNJGqvgVUYI08=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=iUgfICh/IXyMZutQsVhAnenm+aqYjxz0CX3rNsnaYA42x7vHjAOcq4GM5meTnyTtP/Nf5YbdhqKY8VOVPx0/1Lj0RUP09lP5CADBYQPdv9sqqgoKisDedFQYy3ygXyW2rb5OJBG0aqksObfoqYzyg0e0Dy1gx5N8XpVM2Zta74E= 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=OKGKmb6j; arc=none smtp.client-ip=209.85.216.74 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="OKGKmb6j" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-327b00af618so64550a91.1 for ; Wed, 27 Aug 2025 17:02:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1756339325; x=1756944125; darn=lists.linux.dev; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=hDymskQNp6wG2uiiMHxVPzsL1nAJPxy4zRxFOrP95kA=; b=OKGKmb6j/uRRVV0zKqtoMMRqLaMcg4SgZHeMh8Rig4FYCK3NINg3VvrzFv9W35W8zU TQZeN1B1FtUVhKgS1UybuBVXChCfESKcC9NMUbpmDWMJnPMEgAcelFsp45r8QHbZXr0P L9nxTmO2Tb36C8W1QR4cuMA1UEK9VKVHCZFh9aTNrSKYvgGZOLoowugsLvU6t3biOLxg qxUlWLdS1pnOPq/39muD1J/yGSR4H9uuoAfMtYhNZsAn4pSKFctjvv4fIdikoO/XcLls o6iLqZWJMgdchz0ZyJszpd7GAOSrg7ny9XyUC4lfQmbIhoRPc8OcKPJvUc0J9SceFlN/ nEiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756339325; x=1756944125; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=hDymskQNp6wG2uiiMHxVPzsL1nAJPxy4zRxFOrP95kA=; b=v5PnWHtI7eYk95K1yzV5ioy06qs0+73sT9xiqHaD5ZPGIGcTeGoMNLn7o2Je6lvYqt Xby/dWPknpFvCLAI4AAmFhS49Yz1HcgJXJlPCHdsXvQ5rPELXXuAZdnrNI8OFj2YR52Q oTHSvxlhubIfqMTRY9zDWRm0eiWGkVoeT7hRYxcQ4o+yomlNouj5/Pj0K8ZA/PHijyv0 4luN96g4gcyowJKK7MDkOCNGl8dAZunr2CLjPF3euLFYjnzhgdUp3l4bcNpp8ftmD1SB FYy84WYbV7sbrG76QeFWvF0DPBymJlTVt2gIPdJkgAClHOPmmTx3FjzfNaf4e1hHockL V8Fw== X-Forwarded-Encrypted: i=1; AJvYcCXEkWOJ9YzmSnWO1+MaZ3mzFImd6za2eUmGWs2amedaQYlnVX20YUJLOqj52IJKhpsCsGqtXRE=@lists.linux.dev X-Gm-Message-State: AOJu0Yy09Det+KWUQF8t+2N7hjJ8HtIYD4rQQOz5H+aQnFTD6J3uxDMT m0+NlSSULGaccvwHP7vqcFuouG8kQCX2YYXmmDHHWqNF/kDFeytLsKDbyCTeg7XASfWn4yeHceB /a8c8Ow== X-Google-Smtp-Source: AGHT+IEpldWCysonYjdHETjodWyZtDlIBYcwDxX/6JZFBAIAnGNdK+zSnqMrfXxPLk2m5pFyKQhTG4/yaKw= X-Received: from pjj15.prod.google.com ([2002:a17:90b:554f:b0:325:833b:6f27]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:55c4:b0:327:aaeb:e814 with SMTP id 98e67ed59e1d1-327aaebf1b1mr940666a91.23.1756339325323; Wed, 27 Aug 2025 17:02:05 -0700 (PDT) Reply-To: Sean Christopherson Date: Wed, 27 Aug 2025 17:01:51 -0700 In-Reply-To: <20250828000156.23389-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250828000156.23389-1-seanjc@google.com> X-Mailer: git-send-email 2.51.0.268.g9569e192d0-goog Message-ID: <20250828000156.23389-3-seanjc@google.com> Subject: [PATCH v2 2/7] Drivers: hv: Disentangle VTL return cancellation from SIGPENDING From: Sean Christopherson To: Marc Zyngier , Oliver Upton , Catalin Marinas , Will Deacon , Tianrui Zhao , Bibo Mao , Huacai Chen , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Sean Christopherson , 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, Nuno Das Neves , Mukesh R Content-Type: text/plain; charset="UTF-8" Check for return to a lower VTL being cancelled separately from handling pending TIF-based work, as there is no need to immediately process pending work; the kernel will immediately exit to userspace (ignoring preemption) and handle the pending work at that time. Disentangling cancellation from the TIF-based work will allow switching to common virtualization APIs for detecting and processing pending work. Signed-off-by: Sean Christopherson --- drivers/hv/mshv_vtl_main.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/hv/mshv_vtl_main.c b/drivers/hv/mshv_vtl_main.c index 12f5e77b7095..aa09a76f0eff 100644 --- a/drivers/hv/mshv_vtl_main.c +++ b/drivers/hv/mshv_vtl_main.c @@ -731,19 +731,21 @@ static int mshv_vtl_ioctl_return_to_lower_vtl(void) _TIF_NOTIFY_RESUME | _TIF_NOTIFY_SIGNAL | _TIF_NEED_RESCHED_LAZY; unsigned long ti_work; - u32 cancel; unsigned long irq_flags; struct hv_vp_assist_page *hvp; int ret; local_irq_save(irq_flags); + if (READ_ONCE(mshv_vtl_this_run()->cancel)) { + local_irq_restore(irq_flags); + preempt_enable(); + return -EINTR; + } + ti_work = READ_ONCE(current_thread_info()->flags); - cancel = READ_ONCE(mshv_vtl_this_run()->cancel); - if (unlikely((ti_work & VTL0_WORK) || cancel)) { + if (unlikely(ti_work & VTL0_WORK)) { local_irq_restore(irq_flags); preempt_enable(); - if (cancel) - ti_work |= _TIF_SIGPENDING; ret = mshv_do_pre_guest_mode_work(ti_work); if (ret) return ret; -- 2.51.0.268.g9569e192d0-goog