Commit 43d8ac22 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

Merge branch kvm-arm64/pkvm-hyp-sharing into kvmarm-master/next 



* kvm-arm64/pkvm-hyp-sharing:
  : .
  : Series from Quentin Perret, implementing HYP page share/unshare:
  :
  : This series implements an unshare hypercall at EL2 in nVHE
  : protected mode, and makes use of it to unmmap guest-specific
  : data-structures from EL2 stage-1 during guest tear-down.
  : Crucially, the implementation of the share and unshare
  : routines use page refcounts in the host kernel to avoid
  : accidentally unmapping data-structures that overlap a common
  : page.
  : [...]
  : .
  KVM: arm64: pkvm: Unshare guest structs during teardown
  KVM: arm64: Expose unshare hypercall to the host
  KVM: arm64: Implement do_unshare() helper for unsharing memory
  KVM: arm64: Implement __pkvm_host_share_hyp() using do_share()
  KVM: arm64: Implement do_share() helper for sharing memory
  KVM: arm64: Introduce wrappers for host and hyp spin lock accessors
  KVM: arm64: Extend pkvm_page_state enumeration to handle absent pages
  KVM: arm64: pkvm: Refcount the pages shared with EL2
  KVM: arm64: Introduce kvm_share_hyp()
  KVM: arm64: Implement kvm_pgtable_hyp_unmap() at EL2
  KVM: arm64: Hook up ->page_count() for hypervisor stage-1 page-table
  KVM: arm64: Fixup hyp stage-1 refcount
  KVM: arm64: Refcount hyp stage-1 pgtable pages
  KVM: arm64: Provide {get,put}_page() stubs for early hyp allocator

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parents ce5b5b05 52b28657

arch/arm64/include/asm/kvm_asm.h

+1 −0
Original line number Diff line number Diff line
@@ -63,6 +63,7 @@ enum __kvm_host_smccc_func { 


	/* Hypercalls available after pKVM finalisation */

	__KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp,

	__KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp,

	__KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,

	__KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,

	__KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,

arch/arm64/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -321,6 +321,7 @@ struct kvm_vcpu_arch { 
	struct kvm_guest_debug_arch external_debug_state;



	struct user_fpsimd_state *host_fpsimd_state;	/* hyp VA */

	struct task_struct *parent_task;



	struct {

		/* {Break,watch}point registers */
@@ -737,6 +738,7 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu); 
void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu);

void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu);

void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu);

void kvm_vcpu_unshare_task_fp(struct kvm_vcpu *vcpu);



static inline bool kvm_pmu_counter_deferred(struct perf_event_attr *attr)

{

arch/arm64/include/asm/kvm_mmu.h

+2 −0
Original line number Diff line number Diff line
@@ -150,6 +150,8 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v) 
#include <asm/kvm_pgtable.h>

#include <asm/stage2_pgtable.h>



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

void kvm_unshare_hyp(void *from, void *to);

int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot);

int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,

			   void __iomem **kaddr,

arch/arm64/include/asm/kvm_pgtable.h

+21 −0
Original line number Diff line number Diff line
@@ -251,6 +251,27 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt); 
int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,

			enum kvm_pgtable_prot prot);



/**

 * kvm_pgtable_hyp_unmap() - Remove a mapping from a hypervisor stage-1 page-table.

 * @pgt:	Page-table structure initialised by kvm_pgtable_hyp_init().

 * @addr:	Virtual address from which to remove the mapping.

 * @size:	Size of the mapping.

 *

 * The offset of @addr within a page is ignored, @size is rounded-up to

 * the next page boundary and @phys is rounded-down to the previous page

 * boundary.

 *

 * TLB invalidation is performed for each page-table entry cleared during the

 * unmapping operation and the reference count for the page-table page

 * containing the cleared entry is decremented, with unreferenced pages being

 * freed. The unmapping operation will stop early if it encounters either an

 * invalid page-table entry or a valid block mapping which maps beyond the range

 * being unmapped.

 *

 * Return: Number of bytes unmapped, which may be 0.

 */

u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size);



/**

 * kvm_get_vtcr() - Helper to construct VTCR_EL2

 * @mmfr0:	Sanitized value of SYS_ID_AA64MMFR0_EL1 register.

arch/arm64/kvm/arm.c

+4 −2
Original line number Diff line number Diff line
@@ -146,7 +146,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) 
	if (ret)

		return ret;



	ret = create_hyp_mappings(kvm, kvm + 1, PAGE_HYP);

	ret = kvm_share_hyp(kvm, kvm + 1);

	if (ret)

		goto out_free_stage2_pgd;
@@ -188,6 +188,8 @@ void kvm_arch_destroy_vm(struct kvm *kvm) 
		}

	}

	atomic_set(&kvm->online_vcpus, 0);



	kvm_unshare_hyp(kvm, kvm + 1);

}



int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
@@ -342,7 +344,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) 
	if (err)

		return err;



	return create_hyp_mappings(vcpu, vcpu + 1, PAGE_HYP);

	return kvm_share_hyp(vcpu, vcpu + 1);

}



void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)