Commit bc3888a0 authored by Will Deacon's avatar Will Deacon Committed by Oliver Upton
Browse files

KVM: arm64: Allocate pages for hypervisor FF-A mailboxes 



The FF-A proxy code needs to allocate its own buffer pair for
communication with EL3 and for forwarding calls from the host at EL1.

Reserve a couple of pages for this purpose and use them to initialise
the hypervisor's FF-A buffer structure.

Co-developed-by: default avatarAndrew Walbran <qwandor@google.com>
Signed-off-by: default avatarAndrew Walbran <qwandor@google.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230523101828.7328-4-will@kernel.org


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent 12bdce4f

arch/arm64/include/asm/kvm_pkvm.h

+8 −0
Original line number Diff line number Diff line
@@ -106,4 +106,12 @@ static inline unsigned long host_s2_pgtable_pages(void) 
	return res;

}



#define KVM_FFA_MBOX_NR_PAGES	1



static inline unsigned long hyp_ffa_proxy_pages(void)

{

	/* A page each for the hypervisor's RX and TX mailboxes. */

	return 2 * KVM_FFA_MBOX_NR_PAGES;

}



#endif	/* __ARM64_KVM_PKVM_H__ */

arch/arm64/kvm/hyp/include/nvhe/ffa.h

+1 −1
Original line number Diff line number Diff line
@@ -11,7 +11,7 @@ 
#define FFA_MIN_FUNC_NUM 0x60

#define FFA_MAX_FUNC_NUM 0x7F



int hyp_ffa_init(void);

int hyp_ffa_init(void *pages);

bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt);



#endif /* __KVM_HYP_FFA_H */

arch/arm64/kvm/hyp/nvhe/ffa.c

+23 −1
Original line number Diff line number Diff line
@@ -28,8 +28,11 @@ 


#include <linux/arm-smccc.h>

#include <linux/arm_ffa.h>

#include <asm/kvm_pkvm.h>



#include <nvhe/ffa.h>

#include <nvhe/trap_handler.h>

#include <nvhe/spinlock.h>



/*

 * "ID value 0 must be returned at the Non-secure physical FF-A instance"
@@ -37,6 +40,19 @@ 
 */

#define HOST_FFA_ID	0



struct kvm_ffa_buffers {

	hyp_spinlock_t lock;

	void *tx;

	void *rx;

};



/*

 * Note that we don't currently lock these buffers explicitly, instead

 * relying on the locking of the host FFA buffers as we only have one

 * client.

 */

static struct kvm_ffa_buffers hyp_buffers;



static void ffa_to_smccc_error(struct arm_smccc_res *res, u64 ffa_errno)

{

	*res = (struct arm_smccc_res) {
@@ -124,7 +140,7 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt) 
	return true;

}



int hyp_ffa_init(void)

int hyp_ffa_init(void *pages)

{

	struct arm_smccc_res res;
@@ -145,5 +161,11 @@ int hyp_ffa_init(void) 
	if (res.a2 != HOST_FFA_ID)

		return -EINVAL;



	hyp_buffers = (struct kvm_ffa_buffers) {

		.lock	= __HYP_SPIN_LOCK_UNLOCKED,

		.tx	= pages,

		.rx	= pages + (KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE),

	};



	return 0;

}

arch/arm64/kvm/hyp/nvhe/setup.c

+7 −1
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ static void *vmemmap_base; 
static void *vm_table_base;

static void *hyp_pgt_base;

static void *host_s2_pgt_base;

static void *ffa_proxy_pages;

static struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops;

static struct hyp_pool hpool;
@@ -58,6 +59,11 @@ static int divide_memory_pool(void *virt, unsigned long size) 
	if (!host_s2_pgt_base)

		return -ENOMEM;



	nr_pages = hyp_ffa_proxy_pages();

	ffa_proxy_pages = hyp_early_alloc_contig(nr_pages);

	if (!ffa_proxy_pages)

		return -ENOMEM;



	return 0;

}
@@ -315,7 +321,7 @@ void __noreturn __pkvm_init_finalise(void) 
	if (ret)

		goto out;



	ret = hyp_ffa_init();

	ret = hyp_ffa_init(ffa_proxy_pages);

	if (ret)

		goto out;

arch/arm64/kvm/pkvm.c

+1 −0
Original line number Diff line number Diff line
@@ -78,6 +78,7 @@ void __init kvm_hyp_reserve(void) 
	hyp_mem_pages += host_s2_pgtable_pages();

	hyp_mem_pages += hyp_vm_table_pages();

	hyp_mem_pages += hyp_vmemmap_pages(STRUCT_HYP_PAGE_SIZE);

	hyp_mem_pages += hyp_ffa_proxy_pages();



	/*

	 * Try to allocate a PMD-aligned region to reduce TLB pressure once