Commit d157f4a5 authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

ARM: KVM: perform HYP initilization for hotplugged CPUs 



Now that we have the necessary infrastructure to boot a hotplugged CPU
at any point in time, wire a CPU notifier that will perform the HYP
init for the incoming CPU.

Note that this depends on the platform code and/or firmware to boot the
incoming CPU with HYP mode enabled and return to the kernel by following
the normal boot path (HYP stub installed).

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <cdall@cs.columbia.edu>
parent 5a677ce0

arch/arm/include/asm/kvm_mmu.h

+1 −0
Original line number Diff line number Diff line
@@ -44,6 +44,7 @@ 


int create_hyp_mappings(void *from, void *to);

int create_hyp_io_mappings(void *from, void *to, phys_addr_t);

void free_boot_hyp_pgd(void);

void free_hyp_pgds(void);



int kvm_alloc_stage2_pgd(struct kvm *kvm);

arch/arm/kvm/arm.c

+34 −15
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

 */



#include <linux/cpu.h>

#include <linux/errno.h>

#include <linux/err.h>

#include <linux/kvm_host.h>
@@ -785,7 +786,7 @@ long kvm_arch_vm_ioctl(struct file *filp, 
	}

}



static void cpu_init_hyp_mode(void *vector)

static void cpu_init_hyp_mode(void *dummy)

{

	unsigned long long boot_pgd_ptr;

	unsigned long long pgd_ptr;
@@ -805,12 +806,28 @@ static void cpu_init_hyp_mode(void *vector) 
	__cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr);

}



static int hyp_init_cpu_notify(struct notifier_block *self,

			       unsigned long action, void *cpu)

{

	switch (action) {

	case CPU_STARTING:

	case CPU_STARTING_FROZEN:

		cpu_init_hyp_mode(NULL);

		break;

	}



	return NOTIFY_OK;

}



static struct notifier_block hyp_init_cpu_nb = {

	.notifier_call = hyp_init_cpu_notify,

};



/**

 * Inits Hyp-mode on all online CPUs

 */

static int init_hyp_mode(void)

{

	phys_addr_t init_phys_addr;

	int cpu;

	int err = 0;
@@ -842,19 +859,6 @@ static int init_hyp_mode(void) 
		per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page;

	}



	/*

	 * Execute the init code on each CPU.

	 *

	 * Note: The stack is not mapped yet, so don't do anything else than

	 * initializing the hypervisor mode on each CPU using a local stack

	 * space for temporary storage.

	 */

	init_phys_addr = virt_to_phys(__kvm_hyp_init);

	for_each_online_cpu(cpu) {

		smp_call_function_single(cpu, cpu_init_hyp_mode,

					 (void *)(long)init_phys_addr, 1);

	}



	/*

	 * Map the Hyp-code called directly from the host

	 */
@@ -899,6 +903,11 @@ static int init_hyp_mode(void) 
		}

	}



	/*

	 * Execute the init code on each CPU.

	 */

	on_each_cpu(cpu_init_hyp_mode, NULL, 1);



	/*

	 * Init HYP view of VGIC

	 */
@@ -917,6 +926,10 @@ static int init_hyp_mode(void) 
	if (err)

		goto out_free_mappings;



#ifndef CONFIG_HOTPLUG_CPU

	free_boot_hyp_pgd();

#endif



	kvm_perf_init();



	kvm_info("Hyp mode initialized successfully\n");
@@ -955,6 +968,12 @@ int kvm_arch_init(void *opaque) 
	if (err)

		goto out_err;



	err = register_cpu_notifier(&hyp_init_cpu_nb);

	if (err) {

		kvm_err("Cannot register HYP init CPU notifier (%d)\n", err);

		goto out_err;

	}



	kvm_coproc_table_init();

	return 0;

out_err:

arch/arm/kvm/mmu.c

+28 −7
Original line number Diff line number Diff line
@@ -155,6 +155,31 @@ static void unmap_range(pgd_t *pgdp, unsigned long long start, u64 size) 
	}

}



/**

 * free_boot_hyp_pgd - free HYP boot page tables

 *

 * Free the HYP boot page tables. The bounce page is also freed.

 */

void free_boot_hyp_pgd(void)

{

	mutex_lock(&kvm_hyp_pgd_mutex);



	if (boot_hyp_pgd) {

		unmap_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);

		unmap_range(boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);

		kfree(boot_hyp_pgd);

		boot_hyp_pgd = NULL;

	}



	if (hyp_pgd)

		unmap_range(hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);



	kfree(init_bounce_page);

	init_bounce_page = NULL;



	mutex_unlock(&kvm_hyp_pgd_mutex);

}



/**

 * free_hyp_pgds - free Hyp-mode page tables

 *
@@ -169,13 +194,9 @@ void free_hyp_pgds(void) 
{

	unsigned long addr;



	mutex_lock(&kvm_hyp_pgd_mutex);

	free_boot_hyp_pgd();



	if (boot_hyp_pgd) {

		unmap_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);

		unmap_range(boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);

		kfree(boot_hyp_pgd);

	}

	mutex_lock(&kvm_hyp_pgd_mutex);



	if (hyp_pgd) {

		for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
@@ -183,9 +204,9 @@ void free_hyp_pgds(void) 
		for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)

			unmap_range(hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);

		kfree(hyp_pgd);

		hyp_pgd = NULL;

	}



	kfree(init_bounce_page);

	mutex_unlock(&kvm_hyp_pgd_mutex);

}

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