Commit 53324b51 authored by Bharata B Rao's avatar Bharata B Rao Committed by Michael Ellerman
Browse files

KVM: PPC: Book3S HV: Nested support in H_RPT_INVALIDATE 



Enable support for process-scoped invalidations from nested
guests and partition-scoped invalidations for nested guests.

Process-scoped invalidations for any level of nested guests
are handled by implementing H_RPT_INVALIDATE handler in the
nested guest exit path in L0.

Partition-scoped invalidation requests are forwarded to the
right nested guest, handled there and passed down to L0
for eventual handling.

Signed-off-by: default avatarBharata B Rao <bharata@linux.ibm.com>
[aneesh: Nested guest partition-scoped invalidation changes]
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Squash in fixup patch]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621085003.904767-5-bharata@linux.ibm.com
parent f0c6fbbb

arch/powerpc/include/asm/book3s/64/tlbflush-radix.h

+4 −0
Original line number Diff line number Diff line
@@ -4,6 +4,10 @@ 


#include <asm/hvcall.h>



#define RIC_FLUSH_TLB 0

#define RIC_FLUSH_PWC 1

#define RIC_FLUSH_ALL 2



struct vm_area_struct;

struct mm_struct;

struct mmu_gather;

arch/powerpc/include/asm/kvm_book3s.h

+3 −0
Original line number Diff line number Diff line
@@ -307,6 +307,9 @@ void kvmhv_set_ptbl_entry(unsigned int lpid, u64 dw0, u64 dw1); 
void kvmhv_release_all_nested(struct kvm *kvm);

long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu);

long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu);

long do_h_rpt_invalidate_pat(struct kvm_vcpu *vcpu, unsigned long lpid,

			     unsigned long type, unsigned long pg_sizes,

			     unsigned long start, unsigned long end);

int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu,

			  u64 time_limit, unsigned long lpcr);

void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr);

arch/powerpc/kvm/book3s_hv.c

+56 −3
Original line number Diff line number Diff line
@@ -923,6 +923,34 @@ static int kvmppc_get_yield_count(struct kvm_vcpu *vcpu) 
	return yield_count;

}



/*

 * H_RPT_INVALIDATE hcall handler for nested guests.

 *

 * Handles only nested process-scoped invalidation requests in L0.

 */

static int kvmppc_nested_h_rpt_invalidate(struct kvm_vcpu *vcpu)

{

	unsigned long type = kvmppc_get_gpr(vcpu, 6);

	unsigned long pid, pg_sizes, start, end;



	/*

	 * The partition-scoped invalidations aren't handled here in L0.

	 */

	if (type & H_RPTI_TYPE_NESTED)

		return RESUME_HOST;



	pid = kvmppc_get_gpr(vcpu, 4);

	pg_sizes = kvmppc_get_gpr(vcpu, 7);

	start = kvmppc_get_gpr(vcpu, 8);

	end = kvmppc_get_gpr(vcpu, 9);



	do_h_rpt_invalidate_prt(pid, vcpu->arch.nested->shadow_lpid,

				type, pg_sizes, start, end);



	kvmppc_set_gpr(vcpu, 3, H_SUCCESS);

	return RESUME_GUEST;

}



static long kvmppc_h_rpt_invalidate(struct kvm_vcpu *vcpu,

				    unsigned long id, unsigned long target,

				    unsigned long type, unsigned long pg_sizes,
@@ -936,10 +964,18 @@ static long kvmppc_h_rpt_invalidate(struct kvm_vcpu *vcpu, 


	/*

	 * Partition-scoped invalidation for nested guests.

	 * Not yet supported

	 */

	if (type & H_RPTI_TYPE_NESTED)

		return H_P3;

	if (type & H_RPTI_TYPE_NESTED) {

		if (!nesting_enabled(vcpu->kvm))

			return H_FUNCTION;



		/* Support only cores as target */

		if (target != H_RPTI_TARGET_CMMU)

			return H_P2;



		return do_h_rpt_invalidate_pat(vcpu, id, type, pg_sizes,

					       start, end);

	}



	/*

	 * Process-scoped invalidation for L1 guests.
@@ -1784,6 +1820,23 @@ static int kvmppc_handle_nested_exit(struct kvm_vcpu *vcpu) 
		if (!xics_on_xive())

			kvmppc_xics_rm_complete(vcpu, 0);

		break;

	case BOOK3S_INTERRUPT_SYSCALL:

	{

		unsigned long req = kvmppc_get_gpr(vcpu, 3);



		/*

		 * The H_RPT_INVALIDATE hcalls issued by nested

		 * guests for process-scoped invalidations when

		 * GTSE=0, are handled here in L0.

		 */

		if (req == H_RPT_INVALIDATE) {

			r = kvmppc_nested_h_rpt_invalidate(vcpu);

			break;

		}



		r = RESUME_HOST;

		break;

	}

	default:

		r = RESUME_HOST;

		break;

arch/powerpc/kvm/book3s_hv_nested.c

+107 −0
Original line number Diff line number Diff line
@@ -1214,6 +1214,113 @@ long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu) 
	return H_SUCCESS;

}



static long do_tlb_invalidate_nested_all(struct kvm_vcpu *vcpu,

					 unsigned long lpid, unsigned long ric)

{

	struct kvm *kvm = vcpu->kvm;

	struct kvm_nested_guest *gp;



	gp = kvmhv_get_nested(kvm, lpid, false);

	if (gp) {

		kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);

		kvmhv_put_nested(gp);

	}

	return H_SUCCESS;

}



/*

 * Number of pages above which we invalidate the entire LPID rather than

 * flush individual pages.

 */

static unsigned long tlb_range_flush_page_ceiling __read_mostly = 33;



static long do_tlb_invalidate_nested_tlb(struct kvm_vcpu *vcpu,

					 unsigned long lpid,

					 unsigned long pg_sizes,

					 unsigned long start,

					 unsigned long end)

{

	int ret = H_P4;

	unsigned long addr, nr_pages;

	struct mmu_psize_def *def;

	unsigned long psize, ap, page_size;

	bool flush_lpid;



	for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {

		def = &mmu_psize_defs[psize];

		if (!(pg_sizes & def->h_rpt_pgsize))

			continue;



		nr_pages = (end - start) >> def->shift;

		flush_lpid = nr_pages > tlb_range_flush_page_ceiling;

		if (flush_lpid)

			return do_tlb_invalidate_nested_all(vcpu, lpid,

							RIC_FLUSH_TLB);

		addr = start;

		ap = mmu_get_ap(psize);

		page_size = 1UL << def->shift;

		do {

			ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap,

						   get_epn(addr));

			if (ret)

				return H_P4;

			addr += page_size;

		} while (addr < end);

	}

	return ret;

}



/*

 * Performs partition-scoped invalidations for nested guests

 * as part of H_RPT_INVALIDATE hcall.

 */

long do_h_rpt_invalidate_pat(struct kvm_vcpu *vcpu, unsigned long lpid,

			     unsigned long type, unsigned long pg_sizes,

			     unsigned long start, unsigned long end)

{

	/*

	 * If L2 lpid isn't valid, we need to return H_PARAMETER.

	 *

	 * However, nested KVM issues a L2 lpid flush call when creating

	 * partition table entries for L2. This happens even before the

	 * corresponding shadow lpid is created in HV which happens in

	 * H_ENTER_NESTED call. Since we can't differentiate this case from

	 * the invalid case, we ignore such flush requests and return success.

	 */

	if (!kvmhv_find_nested(vcpu->kvm, lpid))

		return H_SUCCESS;



	/*

	 * A flush all request can be handled by a full lpid flush only.

	 */

	if ((type & H_RPTI_TYPE_NESTED_ALL) == H_RPTI_TYPE_NESTED_ALL)

		return do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_ALL);



	/*

	 * We don't need to handle a PWC flush like process table here,

	 * because intermediate partition scoped table in nested guest doesn't

	 * really have PWC. Only level we have PWC is in L0 and for nested

	 * invalidate at L0 we always do kvm_flush_lpid() which does

	 * radix__flush_all_lpid(). For range invalidate at any level, we

	 * are not removing the higher level page tables and hence there is

	 * no PWC invalidate needed.

	 *

	 * if (type & H_RPTI_TYPE_PWC) {

	 *	ret = do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_PWC);

	 *	if (ret)

	 *		return H_P4;

	 * }

	 */



	if (start == 0 && end == -1)

		return do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_TLB);



	if (type & H_RPTI_TYPE_TLB)

		return do_tlb_invalidate_nested_tlb(vcpu, lpid, pg_sizes,

						    start, end);

	return H_SUCCESS;

}



/* Used to convert a nested guest real address to a L1 guest real address */

static int kvmhv_translate_addr_nested(struct kvm_vcpu *vcpu,

				       struct kvm_nested_guest *gp,

arch/powerpc/mm/book3s64/radix_tlb.c

+0 −4
Original line number Diff line number Diff line
@@ -20,10 +20,6 @@ 


#include "internal.h"



#define RIC_FLUSH_TLB 0

#define RIC_FLUSH_PWC 1

#define RIC_FLUSH_ALL 2



/*

 * tlbiel instruction for radix, set invalidation

 * i.e., r=1 and is=01 or is=10 or is=11