From: wanghaibin wanghaibin.wang@huawei.com
virt inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8K8HP CVE: NA
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Organize the system-wide unused device IDs to build several device ID pools. Use these pools to manage the reserved device IDs which can be used by virtual devices (without the actual HW device ID).
Signed-off-by: wanghaibin wanghaibin.wang@huawei.com Signed-off-by: Zenghui Yu yuzenghui@huawei.com Signed-off-by: Kunkun Jiang jiangkunkun@huawei.com Signed-off-by: Dongxu Sun sundongxu3@huawei.com --- drivers/irqchip/irq-gic-v3-its.c | 110 +++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 4da706139f9d..f6122b7b3192 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -33,6 +33,7 @@ #include <linux/irqchip.h> #include <linux/irqchip/arm-gic-v3.h> #include <linux/irqchip/arm-gic-v4.h> +#include <linux/pci.h>
#include <asm/cputype.h> #include <asm/exception.h> @@ -43,6 +44,95 @@
#include "irq-gic-common.h"
+/* a reserved bus id region */ +struct plat_rsv_buses { + u8 start; /* the first reserved bus id */ + u8 count; +}; + +/* + * Build a devid pool per reserved bus id region, where all + * device ids should be unused by physical PCI devices. + */ +struct rsv_devid_pool { + struct list_head entry; + + struct plat_rsv_buses buses; + u32 start; + u32 end; + + raw_spinlock_t devid_bm_lock; + unsigned long *devid_bm; +}; + +static LIST_HEAD(rsv_devid_pools); +static DEFINE_RAW_SPINLOCK(rsv_devid_pools_lock); + +/* Do we have usable rsv_devid_pool? Initialized to be true. */ +static bool rsv_devid_pool_cap = true; +static u8 rsv_buses_start, rsv_buses_count; + +static int __init rsv_buses_start_cfg(char *buf) +{ + return kstrtou8(buf, 0, &rsv_buses_start); +} +early_param("irqchip.gicv3_rsv_buses_start", rsv_buses_start_cfg); + +static int __init rsv_buses_count_cfg(char *buf) +{ + return kstrtou8(buf, 0, &rsv_buses_count); +} +early_param("irqchip.gicv3_rsv_buses_count", rsv_buses_count_cfg); + +static void get_rsv_buses_resource(struct plat_rsv_buses *buses) +{ + buses->start = rsv_buses_start; + buses->count = rsv_buses_count; + + /* + * FIXME: There is no architectural way to get the *correct* + * reserved bus id info. + * + * The first thought is to increase the GITS_TYPER.Devbits for + * the usage for virtualization, but this will break all + * command layouts with DeviceID as an argument (e.g., INT). + * + * The second way is to decrease the GITS_TYPER.Devids so that + * SW can pick the unused device IDs for use (these IDs should + * actually be supported at HW level, though not exposed). + * *Or* fetch the information with the help of firmware. They + * are essentially the same way. + */ +} + +static int probe_devid_pool_one(void) +{ + struct rsv_devid_pool *devid_pool; + + devid_pool = kzalloc(sizeof(*devid_pool), GFP_KERNEL); + if (!devid_pool) + return -ENOMEM; + + get_rsv_buses_resource(&devid_pool->buses); + raw_spin_lock_init(&devid_pool->devid_bm_lock); + + devid_pool->start = PCI_DEVID(devid_pool->buses.start, 0); + devid_pool->end = PCI_DEVID(devid_pool->buses.start + devid_pool->buses.count, 0); + + devid_pool->devid_bm = bitmap_zalloc(devid_pool->end - devid_pool->start, + GFP_KERNEL); + if (!devid_pool->devid_bm) { + kfree(devid_pool); + return -ENOMEM; + } + + raw_spin_lock(&rsv_devid_pools_lock); + list_add(&devid_pool->entry, &rsv_devid_pools); + raw_spin_unlock(&rsv_devid_pools_lock); + + return 0; +} + #define ITS_FLAGS_CMDQ_NEEDS_FLUSHING (1ULL << 0) #define ITS_FLAGS_WORKAROUND_CAVIUM_22375 (1ULL << 1) #define ITS_FLAGS_WORKAROUND_CAVIUM_23144 (1ULL << 2) @@ -227,6 +317,20 @@ static int nr_gicr; #define gic_data_rdist_rd_base() (gic_data_rdist()->rd_base) #define gic_data_rdist_vlpi_base() (gic_data_rdist_rd_base() + SZ_128K)
+/* + * Currently we only build *one* devid pool. + */ +static int build_devid_pools(void) +{ + struct its_node *its; + + its = list_first_entry(&its_nodes, struct its_node, entry); + if (readl_relaxed(its->base + GITS_IIDR) != 0x00051736) + return -EINVAL; + + return probe_devid_pool_one(); +} + /* * Skip ITSs that have no vLPIs mapped, unless we're on GICv4.1, as we * always have vSGIs mapped. @@ -5795,6 +5899,12 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists, rdists->has_vlpis = false; pr_err("ITS: Disabling GICv4 support\n"); } + + if (build_devid_pools()) + rsv_devid_pool_cap = false; + + if (rsv_devid_pool_cap) + pr_info("ITS: reserved device id pools enabled\n"); }
register_syscore_ops(&its_syscore_ops);