From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="xAKRMNyA" Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2387294 for ; Fri, 1 Dec 2023 14:24:09 -0800 (PST) Received: by mail-pg1-x54a.google.com with SMTP id 41be03b00d2f7-5c65e666609so52721a12.1 for ; Fri, 01 Dec 2023 14:24:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1701469448; x=1702074248; 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=/EaOyG2WIzsmtRAtj27ai8on7XhQQ3gj4a4UXCtq+eI=; b=xAKRMNyAvhsdmdwsxirPecuic9+vA3FGhqgLEEGD66zfKFy1JE6KnXdXVebXGH6kTI +bW319xynRBprHz49TYRt9f8VxgZt6C6zy7bvx9kyXJD7cMNws8GDnyJjZNa9FzM7v/f JRZbwdRgpCK/OCO/64BEwZOYl404E17RJ4BWzDM1yQm3eaCyeLAuNzI+22jyrYFk8j5d 5XPMUL/gfkpfPDdkcbvD288nftmQ6USSewEbkwR1RFm87YpRIbdpRqD40RKNYSynCqq4 K4tmixrgjYgmD/iwPM77JQhLTMwoo5TUy+JkRV3W/E9hAHKYyaYpVQnEJyuKo64FEYmv SKkg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701469448; x=1702074248; 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=/EaOyG2WIzsmtRAtj27ai8on7XhQQ3gj4a4UXCtq+eI=; b=YZlQu3sgckMIhWKpq5VWgPlcXLV5LUtBVdTpwIuZjfEdQToz7EzOmE0hFnOUl0nsFl oqYWBaXIE9uqqWSzpQVOpNlSsDxppiifLpQCGiFzVza60XTvRDRc+6582w0ZxTExr+oH oLZJmgbjUc3bwPKIrSr6iZkfridG+SREdyI2F+4jgrIQrRc9eaJcATFFkTYVNekixUc7 8sTUzcYWU4j3WJMqw1DpYaBb16LeEBo9eylZTD3KdpP7uvBTYVncfrDBf0FWsF4Vdd4R YuxWNO7xhal3FcYQINsl3ppBflti9lNv6SjI4J9RNHBI5B/3v7HW6abE+6T+I/XhD9va T5hg== X-Gm-Message-State: AOJu0Yx1cBvXnpRXUo5f/Yb+AUwbLefFLl21x4MNF1bYlz1n4qHjwQTL 6/PeIhPsw1McUh3bPT0LXcVwyCaoKMk= X-Google-Smtp-Source: AGHT+IHBKsIe10IjUhxcQAtfYEI4/8c1//xFBlfVjKfiL+tnaRnVczW5eRuthcqEdiVgakMe8USSUyiLSyo= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a63:1402:0:b0:5bd:bcde:c677 with SMTP id u2-20020a631402000000b005bdbcdec677mr4120679pgl.2.1701469448566; Fri, 01 Dec 2023 14:24:08 -0800 (PST) Date: Fri, 1 Dec 2023 14:24:06 -0800 In-Reply-To: <20231129153250.3105359-1-arnd@kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20231129153250.3105359-1-arnd@kernel.org> Message-ID: Subject: Re: [PATCH] KVM: guest-memfd: fix unused-function warning From: Sean Christopherson To: Arnd Bergmann Cc: Paolo Bonzini , Yu Zhang , Isaku Yamahata , Chao Peng , "Kirill A. Shutemov" , Arnd Bergmann , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" On Wed, Nov 29, 2023, Arnd Bergmann wrote: > From: Arnd Bergmann > > With migration disabled, one function becomes unused: > > virt/kvm/guest_memfd.c:262:12: error: 'kvm_gmem_migrate_folio' defined but not used [-Werror=unused-function] > 262 | static int kvm_gmem_migrate_folio(struct address_space *mapping, > | ^~~~~~~~~~~~~~~~~~~~~~ > > Replace the #ifdef around the reference with a corresponding PTR_IF() check > that lets the compiler know how it is otherwise used. > > Fixes: a7800aa80ea4 ("KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory") > Signed-off-by: Arnd Bergmann > --- > virt/kvm/guest_memfd.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c > index 16d58806e913..1a0355b95379 100644 > --- a/virt/kvm/guest_memfd.c > +++ b/virt/kvm/guest_memfd.c > @@ -301,9 +301,8 @@ static int kvm_gmem_error_folio(struct address_space *mapping, > > static const struct address_space_operations kvm_gmem_aops = { > .dirty_folio = noop_dirty_folio, > -#ifdef CONFIG_MIGRATION > - .migrate_folio = kvm_gmem_migrate_folio, > -#endif > + .migrate_folio = PTR_IF(IS_ENABLED(CONFIG_MIGRATION), > + kvm_gmem_migrate_folio), I'd much prefer to just delete the #ifdef, e.g. so that we don't somehow end up running fallback_migrate_folio(). I have no clue why I wrapped the hook with CONFIG_MIGRATION.