Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756235Ab1DTUbp (ORCPT ); Wed, 20 Apr 2011 16:31:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12895 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756216Ab1DTUbn (ORCPT ); Wed, 20 Apr 2011 16:31:43 -0400 From: Alex Williamson Subject: [PATCH v3 2/3] PCI: Add interfaces to store and load the device saved state To: linux-pci@vger.kernel.org, kvm@vger.kernel.org, avi@redhat.com Cc: linux-kernel@vger.kernel.org, alex.williamson@redhat.com, jan.kiszka@siemens.com, jbarnes@virtuousgeek.org Date: Wed, 20 Apr 2011 14:31:39 -0600 Message-ID: <20110420203139.3189.89418.stgit@s20.home> In-Reply-To: <20110420202523.3189.31306.stgit@s20.home> References: <20110420202523.3189.31306.stgit@s20.home> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4806 Lines: 145 For KVM device assignment, we'd like to save off the state of a device prior to passing it to the guest and restore it later. We also want to allow pci_reset_funciton() to be called while the device is owned by the guest. This however overwrites and invalidates the struct pci_dev buffers, so we can't just manually call save and restore. Add generic interfaces for the saved state to be stored and reloaded back into struct pci_dev at a later time. Signed-off-by: Alex Williamson --- drivers/pci/pci.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 4 ++ 2 files changed, 102 insertions(+), 0 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index d2500a0..7631acf 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -976,6 +976,104 @@ void pci_restore_state(struct pci_dev *dev) dev->state_saved = false; } +struct pci_saved_state { + u32 config_space[16]; + struct pci_cap_saved cap_saved[0]; +}; + +/** + * pci_store_saved_state - Allocate and return an opaque struct containing + * the device saved state. + * @dev: PCI device that we're dealing with + * + * Rerturn NULL if no state or error. + */ +struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev) +{ + struct pci_saved_state *state; + struct pci_cap_saved_state *tmp; + struct pci_cap_saved *cap_saved; + struct hlist_node *pos; + size_t size; + + if (!dev->state_saved) + return NULL; + + size = sizeof(*state) + sizeof(struct pci_cap_saved); + + hlist_for_each_entry(tmp, pos, &dev->saved_cap_space, next) + size += sizeof(struct pci_cap_saved) + tmp->saved.size; + + state = kzalloc(size, GFP_KERNEL); + if (!state) + return NULL; + + memcpy(state->config_space, dev->saved_config_space, + sizeof(state->config_space)); + + cap_saved = state->cap_saved; + hlist_for_each_entry(tmp, pos, &dev->saved_cap_space, next) { + size_t len = sizeof(struct pci_cap_saved) + tmp->saved.size; + memcpy(cap_saved, &tmp->saved, len); + cap_saved = (struct pci_cap_saved *)((u8 *)cap_saved + len); + } + /* Empty cap_save terminates list */ + + return state; +} +EXPORT_SYMBOL_GPL(pci_store_saved_state); + +/** + * pci_load_saved_state - Reload the provided save state into struct pci_dev. + * @dev: PCI device that we're dealing with + * @state: Saved state returned from pci_store_saved_state() + */ +int pci_load_saved_state(struct pci_dev *dev, struct pci_saved_state *state) +{ + struct pci_cap_saved *cap_saved; + + dev->state_saved = false; + + if (!state) + return 0; + + memcpy(dev->saved_config_space, state->config_space, + sizeof(state->config_space)); + + cap_saved = state->cap_saved; + while (cap_saved->size) { + struct pci_cap_saved_state *tmp; + + tmp = pci_find_saved_cap(dev, cap_saved->cap_nr); + if (!tmp || tmp->saved.size != cap_saved->size) + return -EINVAL; + + memcpy(tmp->saved.data, cap_saved->data, tmp->saved.size); + cap_saved = (struct pci_cap_saved *)((u8 *)cap_saved + + sizeof(struct pci_cap_saved) + cap_saved->size); + } + + dev->state_saved = true; + return 0; +} +EXPORT_SYMBOL_GPL(pci_load_saved_state); + +/** + * pci_load_and_free_saved_state - Reload the save state pointed to by state, + * and free the memory allocated for it. + * @dev: PCI device that we're dealing with + * @state: Pointer to saved state returned from pci_store_saved_state() + */ +int pci_load_and_free_saved_state(struct pci_dev *dev, + struct pci_saved_state **state) +{ + int ret = pci_load_saved_state(dev, *state); + kfree(*state); + *state = NULL; + return ret; +} +EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state); + static int do_pci_enable_device(struct pci_dev *dev, int bars) { int err; diff --git a/include/linux/pci.h b/include/linux/pci.h index 46fd382..f2a6262 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -812,6 +812,10 @@ size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size); /* Power management related routines */ int pci_save_state(struct pci_dev *dev); void pci_restore_state(struct pci_dev *dev); +struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev); +int pci_load_saved_state(struct pci_dev *dev, struct pci_saved_state *state); +int pci_load_and_free_saved_state(struct pci_dev *dev, + struct pci_saved_state **state); int __pci_complete_power_transition(struct pci_dev *dev, pci_power_t state); int pci_set_power_state(struct pci_dev *dev, pci_power_t state); pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/