Revision 0447378a4a793da008451fad50bc0f93e9675ae6 authored by Marc Orr on 21 June 2018, 00:21:29 UTC, committed by Radim Krčmář on 22 June 2018, 14:46:26 UTC
This patch extends the checks done prior to a nested VM entry. Specifically, it extends the check_vmentry_prereqs function with checks for fields relevant to the VM-entry event injection information, as described in the Intel SDM, volume 3. This patch is motivated by a syzkaller bug, where a bad VM-entry interruption information field is generated in the VMCS02, which causes the nested VM launch to fail. Then, KVM fails to resume L1. While KVM should be improved to correctly resume L1 execution after a failed nested launch, this change is justified because the existing code to resume L1 is flaky/ad-hoc and the test coverage for resuming L1 is sparse. Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Marc Orr <marcorr@google.com> [Removed comment whose parts were describing previous revisions and the rest was obvious from function/variable naming. - Radim] Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
1 parent 5f9077c
devres.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/gfp.h>
#include <linux/irq.h>
#include "internals.h"
/*
* Device resource management aware IRQ request/free implementation.
*/
struct irq_devres {
unsigned int irq;
void *dev_id;
};
static void devm_irq_release(struct device *dev, void *res)
{
struct irq_devres *this = res;
free_irq(this->irq, this->dev_id);
}
static int devm_irq_match(struct device *dev, void *res, void *data)
{
struct irq_devres *this = res, *match = data;
return this->irq == match->irq && this->dev_id == match->dev_id;
}
/**
* devm_request_threaded_irq - allocate an interrupt line for a managed device
* @dev: device to request interrupt for
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs
* @thread_fn: function to be called in a threaded interrupt context. NULL
* for devices which handle everything in @handler
* @irqflags: Interrupt type flags
* @devname: An ascii name for the claiming device, dev_name(dev) if NULL
* @dev_id: A cookie passed back to the handler function
*
* Except for the extra @dev argument, this function takes the
* same arguments and performs the same function as
* request_threaded_irq(). IRQs requested with this function will be
* automatically freed on driver detach.
*
* If an IRQ allocated with this function needs to be freed
* separately, devm_free_irq() must be used.
*/
int devm_request_threaded_irq(struct device *dev, unsigned int irq,
irq_handler_t handler, irq_handler_t thread_fn,
unsigned long irqflags, const char *devname,
void *dev_id)
{
struct irq_devres *dr;
int rc;
dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
GFP_KERNEL);
if (!dr)
return -ENOMEM;
if (!devname)
devname = dev_name(dev);
rc = request_threaded_irq(irq, handler, thread_fn, irqflags, devname,
dev_id);
if (rc) {
devres_free(dr);
return rc;
}
dr->irq = irq;
dr->dev_id = dev_id;
devres_add(dev, dr);
return 0;
}
EXPORT_SYMBOL(devm_request_threaded_irq);
/**
* devm_request_any_context_irq - allocate an interrupt line for a managed device
* @dev: device to request interrupt for
* @irq: Interrupt line to allocate
* @handler: Function to be called when the IRQ occurs
* @thread_fn: function to be called in a threaded interrupt context. NULL
* for devices which handle everything in @handler
* @irqflags: Interrupt type flags
* @devname: An ascii name for the claiming device, dev_name(dev) if NULL
* @dev_id: A cookie passed back to the handler function
*
* Except for the extra @dev argument, this function takes the
* same arguments and performs the same function as
* request_any_context_irq(). IRQs requested with this function will be
* automatically freed on driver detach.
*
* If an IRQ allocated with this function needs to be freed
* separately, devm_free_irq() must be used.
*/
int devm_request_any_context_irq(struct device *dev, unsigned int irq,
irq_handler_t handler, unsigned long irqflags,
const char *devname, void *dev_id)
{
struct irq_devres *dr;
int rc;
dr = devres_alloc(devm_irq_release, sizeof(struct irq_devres),
GFP_KERNEL);
if (!dr)
return -ENOMEM;
if (!devname)
devname = dev_name(dev);
rc = request_any_context_irq(irq, handler, irqflags, devname, dev_id);
if (rc < 0) {
devres_free(dr);
return rc;
}
dr->irq = irq;
dr->dev_id = dev_id;
devres_add(dev, dr);
return rc;
}
EXPORT_SYMBOL(devm_request_any_context_irq);
/**
* devm_free_irq - free an interrupt
* @dev: device to free interrupt for
* @irq: Interrupt line to free
* @dev_id: Device identity to free
*
* Except for the extra @dev argument, this function takes the
* same arguments and performs the same function as free_irq().
* This function instead of free_irq() should be used to manually
* free IRQs allocated with devm_request_irq().
*/
void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id)
{
struct irq_devres match_data = { irq, dev_id };
WARN_ON(devres_destroy(dev, devm_irq_release, devm_irq_match,
&match_data));
free_irq(irq, dev_id);
}
EXPORT_SYMBOL(devm_free_irq);
struct irq_desc_devres {
unsigned int from;
unsigned int cnt;
};
static void devm_irq_desc_release(struct device *dev, void *res)
{
struct irq_desc_devres *this = res;
irq_free_descs(this->from, this->cnt);
}
/**
* __devm_irq_alloc_descs - Allocate and initialize a range of irq descriptors
* for a managed device
* @dev: Device to allocate the descriptors for
* @irq: Allocate for specific irq number if irq >= 0
* @from: Start the search from this irq number
* @cnt: Number of consecutive irqs to allocate
* @node: Preferred node on which the irq descriptor should be allocated
* @owner: Owning module (can be NULL)
* @affinity: Optional pointer to an affinity mask array of size @cnt
* which hints where the irq descriptors should be allocated
* and which default affinities to use
*
* Returns the first irq number or error code.
*
* Note: Use the provided wrappers (devm_irq_alloc_desc*) for simplicity.
*/
int __devm_irq_alloc_descs(struct device *dev, int irq, unsigned int from,
unsigned int cnt, int node, struct module *owner,
const struct cpumask *affinity)
{
struct irq_desc_devres *dr;
int base;
dr = devres_alloc(devm_irq_desc_release, sizeof(*dr), GFP_KERNEL);
if (!dr)
return -ENOMEM;
base = __irq_alloc_descs(irq, from, cnt, node, owner, affinity);
if (base < 0) {
devres_free(dr);
return base;
}
dr->from = base;
dr->cnt = cnt;
devres_add(dev, dr);
return base;
}
EXPORT_SYMBOL_GPL(__devm_irq_alloc_descs);
#ifdef CONFIG_GENERIC_IRQ_CHIP
/**
* devm_irq_alloc_generic_chip - Allocate and initialize a generic chip
* for a managed device
* @dev: Device to allocate the generic chip for
* @name: Name of the irq chip
* @num_ct: Number of irq_chip_type instances associated with this
* @irq_base: Interrupt base nr for this chip
* @reg_base: Register base address (virtual)
* @handler: Default flow handler associated with this chip
*
* Returns an initialized irq_chip_generic structure. The chip defaults
* to the primary (index 0) irq_chip_type and @handler
*/
struct irq_chip_generic *
devm_irq_alloc_generic_chip(struct device *dev, const char *name, int num_ct,
unsigned int irq_base, void __iomem *reg_base,
irq_flow_handler_t handler)
{
struct irq_chip_generic *gc;
unsigned long sz = sizeof(*gc) + num_ct * sizeof(struct irq_chip_type);
gc = devm_kzalloc(dev, sz, GFP_KERNEL);
if (gc)
irq_init_generic_chip(gc, name, num_ct,
irq_base, reg_base, handler);
return gc;
}
EXPORT_SYMBOL_GPL(devm_irq_alloc_generic_chip);
struct irq_generic_chip_devres {
struct irq_chip_generic *gc;
u32 msk;
unsigned int clr;
unsigned int set;
};
static void devm_irq_remove_generic_chip(struct device *dev, void *res)
{
struct irq_generic_chip_devres *this = res;
irq_remove_generic_chip(this->gc, this->msk, this->clr, this->set);
}
/**
* devm_irq_setup_generic_chip - Setup a range of interrupts with a generic
* chip for a managed device
*
* @dev: Device to setup the generic chip for
* @gc: Generic irq chip holding all data
* @msk: Bitmask holding the irqs to initialize relative to gc->irq_base
* @flags: Flags for initialization
* @clr: IRQ_* bits to clear
* @set: IRQ_* bits to set
*
* Set up max. 32 interrupts starting from gc->irq_base. Note, this
* initializes all interrupts to the primary irq_chip_type and its
* associated handler.
*/
int devm_irq_setup_generic_chip(struct device *dev, struct irq_chip_generic *gc,
u32 msk, enum irq_gc_flags flags,
unsigned int clr, unsigned int set)
{
struct irq_generic_chip_devres *dr;
dr = devres_alloc(devm_irq_remove_generic_chip,
sizeof(*dr), GFP_KERNEL);
if (!dr)
return -ENOMEM;
irq_setup_generic_chip(gc, msk, flags, clr, set);
dr->gc = gc;
dr->msk = msk;
dr->clr = clr;
dr->set = set;
devres_add(dev, dr);
return 0;
}
EXPORT_SYMBOL_GPL(devm_irq_setup_generic_chip);
#endif /* CONFIG_GENERIC_IRQ_CHIP */
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