From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3839A3A291; Fri, 21 Nov 2025 13:35:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763732104; cv=none; b=J0vUfscEJvcPTIHaJjcqaS9/N2FdWqpU6BLPopzbiLgis/qfMn2bi6gXdBVyh6JOdCzLnENZTBpRMQwXGq1EafrhOtJ95mpE29WKrwond1p+yAKeviu/wc+7LmvkCeT5vxJWMxKG+NgBJS+1yUAIc/0IAlOm37gdKvfMEn8K9RQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763732104; c=relaxed/simple; bh=8q7GOzJ7SFoCJ6yEudiumBf4YmSMChO9s/ufYW5xA8Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GAyTz2hT6wpjI/Rh7Jm6YIqolDb9UHi0F6QxI1mTF71m5YF5RtFwRQf4iU17O5qDmCwW2a+imZgn/ykxLJ9ezuGSknNqLr14kjAFmLnWiInDvxALlVwhQ+0VtoE7FFgy/7IWMAdzsWd9KrGbu0D1aB1u8MCX5XxnaVjQ3YrPk3U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=l9W7vID6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="l9W7vID6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 69BA3C4CEF1; Fri, 21 Nov 2025 13:35:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1763732102; bh=8q7GOzJ7SFoCJ6yEudiumBf4YmSMChO9s/ufYW5xA8Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l9W7vID6i+DFLwtQR/ru2wvZoITKsDdrekP1A7TujSr9KwbWhMICdGB939QViygZ5 L6TwnwMBEBLe4f5zmHb+VevjkEvY9o0CzKpocOoBbNj0Jse3vPzm+2+fSbrMyXKtL8 5LfPVjziiCrVjCwNCZzyF6ZIbs2d3vg8Y5fBCxak= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sean Christopherson , Dmitry Osipenko , Paolo Bonzini , Sasha Levin Subject: [PATCH 6.12 163/185] KVM: guest_memfd: Pass index, not gfn, to __kvm_gmem_get_pfn() Date: Fri, 21 Nov 2025 14:13:10 +0100 Message-ID: <20251121130149.759327833@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251121130143.857798067@linuxfoundation.org> References: <20251121130143.857798067@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Christopherson [ Upstream commit 4af18dc6a9204464db76d9771d1f40e2b46bf6ae ] Refactor guest_memfd usage of __kvm_gmem_get_pfn() to pass the index into the guest_memfd file instead of the gfn, i.e. resolve the index based on the slot+gfn in the caller instead of in __kvm_gmem_get_pfn(). This will allow kvm_gmem_get_pfn() to retrieve and return the specific "struct page", which requires the index into the folio, without a redoing the index calculation multiple times (which isn't costly, just hard to follow). Opportunistically add a kvm_gmem_get_index() helper to make the copy+pasted code easier to understand. Signed-off-by: Sean Christopherson Tested-by: Dmitry Osipenko Signed-off-by: Paolo Bonzini Message-ID: <20241010182427.1434605-46-seanjc@google.com> Stable-dep-of: ae431059e75d ("KVM: guest_memfd: Remove bindings on memslot deletion when gmem is dying") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- virt/kvm/guest_memfd.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -304,6 +304,11 @@ static inline struct file *kvm_gmem_get_ return get_file_active(&slot->gmem.file); } +static pgoff_t kvm_gmem_get_index(struct kvm_memory_slot *slot, gfn_t gfn) +{ + return gfn - slot->base_gfn + slot->gmem.pgoff; +} + static struct file_operations kvm_gmem_fops = { .open = generic_file_open, .release = kvm_gmem_release, @@ -553,12 +558,11 @@ void kvm_gmem_unbind(struct kvm_memory_s } /* Returns a locked folio on success. */ -static struct folio * -__kvm_gmem_get_pfn(struct file *file, struct kvm_memory_slot *slot, - gfn_t gfn, kvm_pfn_t *pfn, bool *is_prepared, - int *max_order) +static struct folio *__kvm_gmem_get_pfn(struct file *file, + struct kvm_memory_slot *slot, + pgoff_t index, kvm_pfn_t *pfn, + bool *is_prepared, int *max_order) { - pgoff_t index = gfn - slot->base_gfn + slot->gmem.pgoff; struct kvm_gmem *gmem = file->private_data; struct folio *folio; @@ -594,6 +598,7 @@ __kvm_gmem_get_pfn(struct file *file, st int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn, kvm_pfn_t *pfn, int *max_order) { + pgoff_t index = kvm_gmem_get_index(slot, gfn); struct file *file = kvm_gmem_get_file(slot); struct folio *folio; bool is_prepared = false; @@ -602,7 +607,7 @@ int kvm_gmem_get_pfn(struct kvm *kvm, st if (!file) return -EFAULT; - folio = __kvm_gmem_get_pfn(file, slot, gfn, pfn, &is_prepared, max_order); + folio = __kvm_gmem_get_pfn(file, slot, index, pfn, &is_prepared, max_order); if (IS_ERR(folio)) { r = PTR_ERR(folio); goto out; @@ -650,6 +655,7 @@ long kvm_gmem_populate(struct kvm *kvm, for (i = 0; i < npages; i += (1 << max_order)) { struct folio *folio; gfn_t gfn = start_gfn + i; + pgoff_t index = kvm_gmem_get_index(slot, gfn); bool is_prepared = false; kvm_pfn_t pfn; @@ -658,7 +664,7 @@ long kvm_gmem_populate(struct kvm *kvm, break; } - folio = __kvm_gmem_get_pfn(file, slot, gfn, &pfn, &is_prepared, &max_order); + folio = __kvm_gmem_get_pfn(file, slot, index, &pfn, &is_prepared, &max_order); if (IS_ERR(folio)) { ret = PTR_ERR(folio); break;