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linux/arch/powerpc/kvm/book3s_hv_nested.c
Nicholas Piggin d9c57d3ed5 KVM: PPC: Book3S HV Nested: Sanitise H_ENTER_NESTED TM state 
The H_ENTER_NESTED hypercall is handled by the L0, and it is a request
by the L1 to switch the context of the vCPU over to that of its L2
guest, and return with an interrupt indication. The L1 is responsible
for switching some registers to guest context, and the L0 switches
others (including all the hypervisor privileged state).

If the L2 MSR has TM active, then the L1 is responsible for
recheckpointing the L2 TM state. Then the L1 exits to L0 via the
H_ENTER_NESTED hcall, and the L0 saves the TM state as part of the exit,
and then it recheckpoints the TM state as part of the nested entry and
finally HRFIDs into the L2 with TM active MSR. Not efficient, but about
the simplest approach for something that's horrendously complicated.

Problems arise if the L1 exits to the L0 with a TM state which does not
match the L2 TM state being requested. For example if the L1 is
transactional but the L2 MSR is non-transactional, or vice versa. The
L0's HRFID can take a TM Bad Thing interrupt and crash.

Fix this by disallowing H_ENTER_NESTED in TM[T] state entirely, and then
ensuring that if the L1 is suspended then the L2 must have TM active,
and if the L1 is not suspended then the L2 must not have TM active.

Fixes: 360cae3137 ("KVM: PPC: Book3S HV: Nested guest entry via hypercall")
Cc: stable@vger.kernel.org # v4.20+
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2021-07-23 16:19:38 +10:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright IBM Corporation, 2018
* Authors Suraj Jitindar Singh <sjitindarsingh@gmail.com>
* Paul Mackerras <paulus@ozlabs.org>
*
* Description: KVM functions specific to running nested KVM-HV guests
* on Book3S processors (specifically POWER9 and later).
*/
#include <linux/kernel.h>
#include <linux/kvm_host.h>
#include <linux/llist.h>
#include <linux/pgtable.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/mmu.h>
#include <asm/pgalloc.h>
#include <asm/pte-walk.h>
#include <asm/reg.h>
#include <asm/plpar_wrappers.h>
static struct patb_entry *pseries_partition_tb;
static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp);
static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free);
void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
hr->pcr = vc->pcr | PCR_MASK;
hr->dpdes = vc->dpdes;
hr->hfscr = vcpu->arch.hfscr;
hr->tb_offset = vc->tb_offset;
hr->dawr0 = vcpu->arch.dawr0;
hr->dawrx0 = vcpu->arch.dawrx0;
hr->ciabr = vcpu->arch.ciabr;
hr->purr = vcpu->arch.purr;
hr->spurr = vcpu->arch.spurr;
hr->ic = vcpu->arch.ic;
hr->vtb = vc->vtb;
hr->srr0 = vcpu->arch.shregs.srr0;
hr->srr1 = vcpu->arch.shregs.srr1;
hr->sprg[0] = vcpu->arch.shregs.sprg0;
hr->sprg[1] = vcpu->arch.shregs.sprg1;
hr->sprg[2] = vcpu->arch.shregs.sprg2;
hr->sprg[3] = vcpu->arch.shregs.sprg3;
hr->pidr = vcpu->arch.pid;
hr->cfar = vcpu->arch.cfar;
hr->ppr = vcpu->arch.ppr;
hr->dawr1 = vcpu->arch.dawr1;
hr->dawrx1 = vcpu->arch.dawrx1;
}
/* Use noinline_for_stack due to https://bugs.llvm.org/show_bug.cgi?id=49610 */
static noinline_for_stack void byteswap_pt_regs(struct pt_regs *regs)
{
unsigned long *addr = (unsigned long *) regs;
for (; addr < ((unsigned long *) (regs + 1)); addr++)
*addr = swab64(*addr);
}
static void byteswap_hv_regs(struct hv_guest_state *hr)
{
hr->version = swab64(hr->version);
hr->lpid = swab32(hr->lpid);
hr->vcpu_token = swab32(hr->vcpu_token);
hr->lpcr = swab64(hr->lpcr);
hr->pcr = swab64(hr->pcr) | PCR_MASK;
hr->amor = swab64(hr->amor);
hr->dpdes = swab64(hr->dpdes);
hr->hfscr = swab64(hr->hfscr);
hr->tb_offset = swab64(hr->tb_offset);
hr->dawr0 = swab64(hr->dawr0);
hr->dawrx0 = swab64(hr->dawrx0);
hr->ciabr = swab64(hr->ciabr);
hr->hdec_expiry = swab64(hr->hdec_expiry);
hr->purr = swab64(hr->purr);
hr->spurr = swab64(hr->spurr);
hr->ic = swab64(hr->ic);
hr->vtb = swab64(hr->vtb);
hr->hdar = swab64(hr->hdar);
hr->hdsisr = swab64(hr->hdsisr);
hr->heir = swab64(hr->heir);
hr->asdr = swab64(hr->asdr);
hr->srr0 = swab64(hr->srr0);
hr->srr1 = swab64(hr->srr1);
hr->sprg[0] = swab64(hr->sprg[0]);
hr->sprg[1] = swab64(hr->sprg[1]);
hr->sprg[2] = swab64(hr->sprg[2]);
hr->sprg[3] = swab64(hr->sprg[3]);
hr->pidr = swab64(hr->pidr);
hr->cfar = swab64(hr->cfar);
hr->ppr = swab64(hr->ppr);
hr->dawr1 = swab64(hr->dawr1);
hr->dawrx1 = swab64(hr->dawrx1);
}
static void save_hv_return_state(struct kvm_vcpu *vcpu, int trap,
struct hv_guest_state *hr)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
hr->dpdes = vc->dpdes;
hr->hfscr = vcpu->arch.hfscr;
hr->purr = vcpu->arch.purr;
hr->spurr = vcpu->arch.spurr;
hr->ic = vcpu->arch.ic;
hr->vtb = vc->vtb;
hr->srr0 = vcpu->arch.shregs.srr0;
hr->srr1 = vcpu->arch.shregs.srr1;
hr->sprg[0] = vcpu->arch.shregs.sprg0;
hr->sprg[1] = vcpu->arch.shregs.sprg1;
hr->sprg[2] = vcpu->arch.shregs.sprg2;
hr->sprg[3] = vcpu->arch.shregs.sprg3;
hr->pidr = vcpu->arch.pid;
hr->cfar = vcpu->arch.cfar;
hr->ppr = vcpu->arch.ppr;
switch (trap) {
case BOOK3S_INTERRUPT_H_DATA_STORAGE:
hr->hdar = vcpu->arch.fault_dar;
hr->hdsisr = vcpu->arch.fault_dsisr;
hr->asdr = vcpu->arch.fault_gpa;
break;
case BOOK3S_INTERRUPT_H_INST_STORAGE:
hr->asdr = vcpu->arch.fault_gpa;
break;
case BOOK3S_INTERRUPT_H_EMUL_ASSIST:
hr->heir = vcpu->arch.emul_inst;
break;
}
}
/*
* This can result in some L0 HV register state being leaked to an L1
* hypervisor when the hv_guest_state is copied back to the guest after
* being modified here.
*
* There is no known problem with such a leak, and in many cases these
* register settings could be derived by the guest by observing behaviour
* and timing, interrupts, etc., but it is an issue to consider.
*/
static void sanitise_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
u64 mask;
/*
* Don't let L1 change LPCR bits for the L2 except these:
*/
mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD |
LPCR_LPES | LPCR_MER;
/*
* Additional filtering is required depending on hardware
* and configuration.
*/
hr->lpcr = kvmppc_filter_lpcr_hv(vcpu->kvm,
(vc->lpcr & ~mask) | (hr->lpcr & mask));
/*
* Don't let L1 enable features for L2 which we've disabled for L1,
* but preserve the interrupt cause field.
*/
hr->hfscr &= (HFSCR_INTR_CAUSE | vcpu->arch.hfscr);
/* Don't let data address watchpoint match in hypervisor state */
hr->dawrx0 &= ~DAWRX_HYP;
hr->dawrx1 &= ~DAWRX_HYP;
/* Don't let completed instruction address breakpt match in HV state */
if ((hr->ciabr & CIABR_PRIV) == CIABR_PRIV_HYPER)
hr->ciabr &= ~CIABR_PRIV;
}
static void restore_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
vc->pcr = hr->pcr | PCR_MASK;
vc->dpdes = hr->dpdes;
vcpu->arch.hfscr = hr->hfscr;
vcpu->arch.dawr0 = hr->dawr0;
vcpu->arch.dawrx0 = hr->dawrx0;
vcpu->arch.ciabr = hr->ciabr;
vcpu->arch.purr = hr->purr;
vcpu->arch.spurr = hr->spurr;
vcpu->arch.ic = hr->ic;
vc->vtb = hr->vtb;
vcpu->arch.shregs.srr0 = hr->srr0;
vcpu->arch.shregs.srr1 = hr->srr1;
vcpu->arch.shregs.sprg0 = hr->sprg[0];
vcpu->arch.shregs.sprg1 = hr->sprg[1];
vcpu->arch.shregs.sprg2 = hr->sprg[2];
vcpu->arch.shregs.sprg3 = hr->sprg[3];
vcpu->arch.pid = hr->pidr;
vcpu->arch.cfar = hr->cfar;
vcpu->arch.ppr = hr->ppr;
vcpu->arch.dawr1 = hr->dawr1;
vcpu->arch.dawrx1 = hr->dawrx1;
}
void kvmhv_restore_hv_return_state(struct kvm_vcpu *vcpu,
struct hv_guest_state *hr)
{
struct kvmppc_vcore *vc = vcpu->arch.vcore;
vc->dpdes = hr->dpdes;
vcpu->arch.hfscr = hr->hfscr;
vcpu->arch.purr = hr->purr;
vcpu->arch.spurr = hr->spurr;
vcpu->arch.ic = hr->ic;
vc->vtb = hr->vtb;
vcpu->arch.fault_dar = hr->hdar;
vcpu->arch.fault_dsisr = hr->hdsisr;
vcpu->arch.fault_gpa = hr->asdr;
vcpu->arch.emul_inst = hr->heir;
vcpu->arch.shregs.srr0 = hr->srr0;
vcpu->arch.shregs.srr1 = hr->srr1;
vcpu->arch.shregs.sprg0 = hr->sprg[0];
vcpu->arch.shregs.sprg1 = hr->sprg[1];
vcpu->arch.shregs.sprg2 = hr->sprg[2];
vcpu->arch.shregs.sprg3 = hr->sprg[3];
vcpu->arch.pid = hr->pidr;
vcpu->arch.cfar = hr->cfar;
vcpu->arch.ppr = hr->ppr;
}
static void kvmhv_nested_mmio_needed(struct kvm_vcpu *vcpu, u64 regs_ptr)
{
/* No need to reflect the page fault to L1, we've handled it */
vcpu->arch.trap = 0;
/*
* Since the L2 gprs have already been written back into L1 memory when
* we complete the mmio, store the L1 memory location of the L2 gpr
* being loaded into by the mmio so that the loaded value can be
* written there in kvmppc_complete_mmio_load()
*/
if (((vcpu->arch.io_gpr & KVM_MMIO_REG_EXT_MASK) == KVM_MMIO_REG_GPR)
&& (vcpu->mmio_is_write == 0)) {
vcpu->arch.nested_io_gpr = (gpa_t) regs_ptr +
offsetof(struct pt_regs,
gpr[vcpu->arch.io_gpr]);
vcpu->arch.io_gpr = KVM_MMIO_REG_NESTED_GPR;
}
}
static int kvmhv_read_guest_state_and_regs(struct kvm_vcpu *vcpu,
struct hv_guest_state *l2_hv,
struct pt_regs *l2_regs,
u64 hv_ptr, u64 regs_ptr)
{
int size;
if (kvm_vcpu_read_guest(vcpu, hv_ptr, &l2_hv->version,
sizeof(l2_hv->version)))
return -1;
if (kvmppc_need_byteswap(vcpu))
l2_hv->version = swab64(l2_hv->version);
size = hv_guest_state_size(l2_hv->version);
if (size < 0)
return -1;
return kvm_vcpu_read_guest(vcpu, hv_ptr, l2_hv, size) ||
kvm_vcpu_read_guest(vcpu, regs_ptr, l2_regs,
sizeof(struct pt_regs));
}
static int kvmhv_write_guest_state_and_regs(struct kvm_vcpu *vcpu,
struct hv_guest_state *l2_hv,
struct pt_regs *l2_regs,
u64 hv_ptr, u64 regs_ptr)
{
int size;
size = hv_guest_state_size(l2_hv->version);
if (size < 0)
return -1;
return kvm_vcpu_write_guest(vcpu, hv_ptr, l2_hv, size) ||
kvm_vcpu_write_guest(vcpu, regs_ptr, l2_regs,
sizeof(struct pt_regs));
}
long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
{
long int err, r;
struct kvm_nested_guest *l2;
struct pt_regs l2_regs, saved_l1_regs;
struct hv_guest_state l2_hv = {0}, saved_l1_hv;
struct kvmppc_vcore *vc = vcpu->arch.vcore;
u64 hv_ptr, regs_ptr;
u64 hdec_exp;
s64 delta_purr, delta_spurr, delta_ic, delta_vtb;
if (vcpu->kvm->arch.l1_ptcr == 0)
return H_NOT_AVAILABLE;
if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr))
return H_BAD_MODE;
/* copy parameters in */
hv_ptr = kvmppc_get_gpr(vcpu, 4);
regs_ptr = kvmppc_get_gpr(vcpu, 5);
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
err = kvmhv_read_guest_state_and_regs(vcpu, &l2_hv, &l2_regs,
hv_ptr, regs_ptr);
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
if (err)
return H_PARAMETER;
if (kvmppc_need_byteswap(vcpu))
byteswap_hv_regs(&l2_hv);
if (l2_hv.version > HV_GUEST_STATE_VERSION)
return H_P2;
if (kvmppc_need_byteswap(vcpu))
byteswap_pt_regs(&l2_regs);
if (l2_hv.vcpu_token >= NR_CPUS)
return H_PARAMETER;
/*
* L1 must have set up a suspended state to enter the L2 in a
* transactional state, and only in that case. These have to be
* filtered out here to prevent causing a TM Bad Thing in the
* host HRFID. We could synthesize a TM Bad Thing back to the L1
* here but there doesn't seem like much point.
*/
if (MSR_TM_SUSPENDED(vcpu->arch.shregs.msr)) {
if (!MSR_TM_ACTIVE(l2_regs.msr))
return H_BAD_MODE;
} else {
if (l2_regs.msr & MSR_TS_MASK)
return H_BAD_MODE;
if (WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_TS_MASK))
return H_BAD_MODE;
}
/* translate lpid */
l2 = kvmhv_get_nested(vcpu->kvm, l2_hv.lpid, true);
if (!l2)
return H_PARAMETER;
if (!l2->l1_gr_to_hr) {
mutex_lock(&l2->tlb_lock);
kvmhv_update_ptbl_cache(l2);
mutex_unlock(&l2->tlb_lock);
}
/* save l1 values of things */
vcpu->arch.regs.msr = vcpu->arch.shregs.msr;
saved_l1_regs = vcpu->arch.regs;
kvmhv_save_hv_regs(vcpu, &saved_l1_hv);
/* convert TB values/offsets to host (L0) values */
hdec_exp = l2_hv.hdec_expiry - vc->tb_offset;
vc->tb_offset += l2_hv.tb_offset;
/* set L1 state to L2 state */
vcpu->arch.nested = l2;
vcpu->arch.nested_vcpu_id = l2_hv.vcpu_token;
vcpu->arch.regs = l2_regs;
/* Guest must always run with ME enabled, HV disabled. */
vcpu->arch.shregs.msr = (vcpu->arch.regs.msr | MSR_ME) & ~MSR_HV;
sanitise_hv_regs(vcpu, &l2_hv);
restore_hv_regs(vcpu, &l2_hv);
vcpu->arch.ret = RESUME_GUEST;
vcpu->arch.trap = 0;
do {
if (mftb() >= hdec_exp) {
vcpu->arch.trap = BOOK3S_INTERRUPT_HV_DECREMENTER;
r = RESUME_HOST;
break;
}
r = kvmhv_run_single_vcpu(vcpu, hdec_exp, l2_hv.lpcr);
} while (is_kvmppc_resume_guest(r));
/* save L2 state for return */
l2_regs = vcpu->arch.regs;
l2_regs.msr = vcpu->arch.shregs.msr;
delta_purr = vcpu->arch.purr - l2_hv.purr;
delta_spurr = vcpu->arch.spurr - l2_hv.spurr;
delta_ic = vcpu->arch.ic - l2_hv.ic;
delta_vtb = vc->vtb - l2_hv.vtb;
save_hv_return_state(vcpu, vcpu->arch.trap, &l2_hv);
/* restore L1 state */
vcpu->arch.nested = NULL;
vcpu->arch.regs = saved_l1_regs;
vcpu->arch.shregs.msr = saved_l1_regs.msr & ~MSR_TS_MASK;
/* set L1 MSR TS field according to L2 transaction state */
if (l2_regs.msr & MSR_TS_MASK)
vcpu->arch.shregs.msr |= MSR_TS_S;
vc->tb_offset = saved_l1_hv.tb_offset;
restore_hv_regs(vcpu, &saved_l1_hv);
vcpu->arch.purr += delta_purr;
vcpu->arch.spurr += delta_spurr;
vcpu->arch.ic += delta_ic;
vc->vtb += delta_vtb;
kvmhv_put_nested(l2);
/* copy l2_hv_state and regs back to guest */
if (kvmppc_need_byteswap(vcpu)) {
byteswap_hv_regs(&l2_hv);
byteswap_pt_regs(&l2_regs);
}
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
err = kvmhv_write_guest_state_and_regs(vcpu, &l2_hv, &l2_regs,
hv_ptr, regs_ptr);
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
if (err)
return H_AUTHORITY;
if (r == -EINTR)
return H_INTERRUPT;
if (vcpu->mmio_needed) {
kvmhv_nested_mmio_needed(vcpu, regs_ptr);
return H_TOO_HARD;
}
return vcpu->arch.trap;
}
long kvmhv_nested_init(void)
{
long int ptb_order;
unsigned long ptcr;
long rc;
if (!kvmhv_on_pseries())
return 0;
if (!radix_enabled())
return -ENODEV;
/* find log base 2 of KVMPPC_NR_LPIDS, rounding up */
ptb_order = __ilog2(KVMPPC_NR_LPIDS - 1) + 1;
if (ptb_order < 8)
ptb_order = 8;
pseries_partition_tb = kmalloc(sizeof(struct patb_entry) << ptb_order,
GFP_KERNEL);
if (!pseries_partition_tb) {
pr_err("kvm-hv: failed to allocated nested partition table\n");
return -ENOMEM;
}
ptcr = __pa(pseries_partition_tb) | (ptb_order - 8);
rc = plpar_hcall_norets(H_SET_PARTITION_TABLE, ptcr);
if (rc != H_SUCCESS) {
pr_err("kvm-hv: Parent hypervisor does not support nesting (rc=%ld)\n",
rc);
kfree(pseries_partition_tb);
pseries_partition_tb = NULL;
return -ENODEV;
}
return 0;
}
void kvmhv_nested_exit(void)
{
/*
* N.B. the kvmhv_on_pseries() test is there because it enables
* the compiler to remove the call to plpar_hcall_norets()
* when CONFIG_PPC_PSERIES=n.
*/
if (kvmhv_on_pseries() && pseries_partition_tb) {
plpar_hcall_norets(H_SET_PARTITION_TABLE, 0);
kfree(pseries_partition_tb);
pseries_partition_tb = NULL;
}
}
static void kvmhv_flush_lpid(unsigned int lpid)
{
long rc;
if (!kvmhv_on_pseries()) {
radix__flush_all_lpid(lpid);
return;
}
if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE))
rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(2, 0, 1),
lpid, TLBIEL_INVAL_SET_LPID);
else
rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
H_RPTI_TYPE_NESTED |
H_RPTI_TYPE_TLB | H_RPTI_TYPE_PWC |
H_RPTI_TYPE_PAT,
H_RPTI_PAGE_ALL, 0, -1UL);
if (rc)
pr_err("KVM: TLB LPID invalidation hcall failed, rc=%ld\n", rc);
}
void kvmhv_set_ptbl_entry(unsigned int lpid, u64 dw0, u64 dw1)
{
if (!kvmhv_on_pseries()) {
mmu_partition_table_set_entry(lpid, dw0, dw1, true);
return;
}
pseries_partition_tb[lpid].patb0 = cpu_to_be64(dw0);
pseries_partition_tb[lpid].patb1 = cpu_to_be64(dw1);
/* L0 will do the necessary barriers */
kvmhv_flush_lpid(lpid);
}
static void kvmhv_set_nested_ptbl(struct kvm_nested_guest *gp)
{
unsigned long dw0;
dw0 = PATB_HR | radix__get_tree_size() |
__pa(gp->shadow_pgtable) | RADIX_PGD_INDEX_SIZE;
kvmhv_set_ptbl_entry(gp->shadow_lpid, dw0, gp->process_table);
}
void kvmhv_vm_nested_init(struct kvm *kvm)
{
kvm->arch.max_nested_lpid = -1;
}
/*
* Handle the H_SET_PARTITION_TABLE hcall.
* r4 = guest real address of partition table + log_2(size) - 12
* (formatted as for the PTCR).
*/
long kvmhv_set_partition_table(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
unsigned long ptcr = kvmppc_get_gpr(vcpu, 4);
int srcu_idx;
long ret = H_SUCCESS;
srcu_idx = srcu_read_lock(&kvm->srcu);
/*
* Limit the partition table to 4096 entries (because that's what
* hardware supports), and check the base address.
*/
if ((ptcr & PRTS_MASK) > 12 - 8 ||
!kvm_is_visible_gfn(vcpu->kvm, (ptcr & PRTB_MASK) >> PAGE_SHIFT))
ret = H_PARAMETER;
srcu_read_unlock(&kvm->srcu, srcu_idx);
if (ret == H_SUCCESS)
kvm->arch.l1_ptcr = ptcr;
return ret;
}
/*
* Handle the H_COPY_TOFROM_GUEST hcall.
* r4 = L1 lpid of nested guest
* r5 = pid
* r6 = eaddr to access
* r7 = to buffer (L1 gpa)
* r8 = from buffer (L1 gpa)
* r9 = n bytes to copy
*/
long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu)
{
struct kvm_nested_guest *gp;
int l1_lpid = kvmppc_get_gpr(vcpu, 4);
int pid = kvmppc_get_gpr(vcpu, 5);
gva_t eaddr = kvmppc_get_gpr(vcpu, 6);
gpa_t gp_to = (gpa_t) kvmppc_get_gpr(vcpu, 7);
gpa_t gp_from = (gpa_t) kvmppc_get_gpr(vcpu, 8);
void *buf;
unsigned long n = kvmppc_get_gpr(vcpu, 9);
bool is_load = !!gp_to;
long rc;
if (gp_to && gp_from) /* One must be NULL to determine the direction */
return H_PARAMETER;
if (eaddr & (0xFFFUL << 52))
return H_PARAMETER;
buf = kzalloc(n, GFP_KERNEL);
if (!buf)
return H_NO_MEM;
gp = kvmhv_get_nested(vcpu->kvm, l1_lpid, false);
if (!gp) {
rc = H_PARAMETER;
goto out_free;
}
mutex_lock(&gp->tlb_lock);
if (is_load) {
/* Load from the nested guest into our buffer */
rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,
eaddr, buf, NULL, n);
if (rc)
goto not_found;
/* Write what was loaded into our buffer back to the L1 guest */
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
rc = kvm_vcpu_write_guest(vcpu, gp_to, buf, n);
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
if (rc)
goto not_found;
} else {
/* Load the data to be stored from the L1 guest into our buf */
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
rc = kvm_vcpu_read_guest(vcpu, gp_from, buf, n);
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
if (rc)
goto not_found;
/* Store from our buffer into the nested guest */
rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,
eaddr, NULL, buf, n);
if (rc)
goto not_found;
}
out_unlock:
mutex_unlock(&gp->tlb_lock);
kvmhv_put_nested(gp);
out_free:
kfree(buf);
return rc;
not_found:
rc = H_NOT_FOUND;
goto out_unlock;
}
/*
* Reload the partition table entry for a guest.
* Caller must hold gp->tlb_lock.
*/
static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp)
{
int ret;
struct patb_entry ptbl_entry;
unsigned long ptbl_addr;
struct kvm *kvm = gp->l1_host;
ret = -EFAULT;
ptbl_addr = (kvm->arch.l1_ptcr & PRTB_MASK) + (gp->l1_lpid << 4);
if (gp->l1_lpid < (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 8))) {
int srcu_idx = srcu_read_lock(&kvm->srcu);
ret = kvm_read_guest(kvm, ptbl_addr,
&ptbl_entry, sizeof(ptbl_entry));
srcu_read_unlock(&kvm->srcu, srcu_idx);
}
if (ret) {
gp->l1_gr_to_hr = 0;
gp->process_table = 0;
} else {
gp->l1_gr_to_hr = be64_to_cpu(ptbl_entry.patb0);
gp->process_table = be64_to_cpu(ptbl_entry.patb1);
}
kvmhv_set_nested_ptbl(gp);
}
static struct kvm_nested_guest *kvmhv_alloc_nested(struct kvm *kvm, unsigned int lpid)
{
struct kvm_nested_guest *gp;
long shadow_lpid;
gp = kzalloc(sizeof(*gp), GFP_KERNEL);
if (!gp)
return NULL;
gp->l1_host = kvm;
gp->l1_lpid = lpid;
mutex_init(&gp->tlb_lock);
gp->shadow_pgtable = pgd_alloc(kvm->mm);
if (!gp->shadow_pgtable)
goto out_free;
shadow_lpid = kvmppc_alloc_lpid();
if (shadow_lpid < 0)
goto out_free2;
gp->shadow_lpid = shadow_lpid;
gp->radix = 1;
memset(gp->prev_cpu, -1, sizeof(gp->prev_cpu));
return gp;
out_free2:
pgd_free(kvm->mm, gp->shadow_pgtable);
out_free:
kfree(gp);
return NULL;
}
/*
* Free up any resources allocated for a nested guest.
*/
static void kvmhv_release_nested(struct kvm_nested_guest *gp)
{
struct kvm *kvm = gp->l1_host;
if (gp->shadow_pgtable) {
/*
* No vcpu is using this struct and no call to
* kvmhv_get_nested can find this struct,
* so we don't need to hold kvm->mmu_lock.
*/
kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable,
gp->shadow_lpid);
pgd_free(kvm->mm, gp->shadow_pgtable);
}
kvmhv_set_ptbl_entry(gp->shadow_lpid, 0, 0);
kvmppc_free_lpid(gp->shadow_lpid);
kfree(gp);
}
static void kvmhv_remove_nested(struct kvm_nested_guest *gp)
{
struct kvm *kvm = gp->l1_host;
int lpid = gp->l1_lpid;
long ref;
spin_lock(&kvm->mmu_lock);
if (gp == kvm->arch.nested_guests[lpid]) {
kvm->arch.nested_guests[lpid] = NULL;
if (lpid == kvm->arch.max_nested_lpid) {
while (--lpid >= 0 && !kvm->arch.nested_guests[lpid])
;
kvm->arch.max_nested_lpid = lpid;
}
--gp->refcnt;
}
ref = gp->refcnt;
spin_unlock(&kvm->mmu_lock);
if (ref == 0)
kvmhv_release_nested(gp);
}
/*
* Free up all nested resources allocated for this guest.
* This is called with no vcpus of the guest running, when
* switching the guest to HPT mode or when destroying the
* guest.
*/
void kvmhv_release_all_nested(struct kvm *kvm)
{
int i;
struct kvm_nested_guest *gp;
struct kvm_nested_guest *freelist = NULL;
struct kvm_memory_slot *memslot;
int srcu_idx;
spin_lock(&kvm->mmu_lock);
for (i = 0; i <= kvm->arch.max_nested_lpid; i++) {
gp = kvm->arch.nested_guests[i];
if (!gp)
continue;
kvm->arch.nested_guests[i] = NULL;
if (--gp->refcnt == 0) {
gp->next = freelist;
freelist = gp;
}
}
kvm->arch.max_nested_lpid = -1;
spin_unlock(&kvm->mmu_lock);
while ((gp = freelist) != NULL) {
freelist = gp->next;
kvmhv_release_nested(gp);
}
srcu_idx = srcu_read_lock(&kvm->srcu);
kvm_for_each_memslot(memslot, kvm_memslots(kvm))
kvmhv_free_memslot_nest_rmap(memslot);
srcu_read_unlock(&kvm->srcu, srcu_idx);
}
/* caller must hold gp->tlb_lock */
static void kvmhv_flush_nested(struct kvm_nested_guest *gp)
{
struct kvm *kvm = gp->l1_host;
spin_lock(&kvm->mmu_lock);
kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, gp->shadow_lpid);
spin_unlock(&kvm->mmu_lock);
kvmhv_flush_lpid(gp->shadow_lpid);
kvmhv_update_ptbl_cache(gp);
if (gp->l1_gr_to_hr == 0)
kvmhv_remove_nested(gp);
}
struct kvm_nested_guest *kvmhv_get_nested(struct kvm *kvm, int l1_lpid,
bool create)
{
struct kvm_nested_guest *gp, *newgp;
if (l1_lpid >= KVM_MAX_NESTED_GUESTS ||
l1_lpid >= (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 12 - 4)))
return NULL;
spin_lock(&kvm->mmu_lock);
gp = kvm->arch.nested_guests[l1_lpid];
if (gp)
++gp->refcnt;
spin_unlock(&kvm->mmu_lock);
if (gp || !create)
return gp;
newgp = kvmhv_alloc_nested(kvm, l1_lpid);
if (!newgp)
return NULL;
spin_lock(&kvm->mmu_lock);
if (kvm->arch.nested_guests[l1_lpid]) {
/* someone else beat us to it */
gp = kvm->arch.nested_guests[l1_lpid];
} else {
kvm->arch.nested_guests[l1_lpid] = newgp;
++newgp->refcnt;
gp = newgp;
newgp = NULL;
if (l1_lpid > kvm->arch.max_nested_lpid)
kvm->arch.max_nested_lpid = l1_lpid;
}
++gp->refcnt;
spin_unlock(&kvm->mmu_lock);
if (newgp)
kvmhv_release_nested(newgp);
return gp;
}
void kvmhv_put_nested(struct kvm_nested_guest *gp)
{
struct kvm *kvm = gp->l1_host;
long ref;
spin_lock(&kvm->mmu_lock);
ref = --gp->refcnt;
spin_unlock(&kvm->mmu_lock);
if (ref == 0)
kvmhv_release_nested(gp);
}
static struct kvm_nested_guest *kvmhv_find_nested(struct kvm *kvm, int lpid)
{
if (lpid > kvm->arch.max_nested_lpid)
return NULL;
return kvm->arch.nested_guests[lpid];
}
pte_t *find_kvm_nested_guest_pte(struct kvm *kvm, unsigned long lpid,
unsigned long ea, unsigned *hshift)
{
struct kvm_nested_guest *gp;
pte_t *pte;
gp = kvmhv_find_nested(kvm, lpid);
if (!gp)
return NULL;
VM_WARN(!spin_is_locked(&kvm->mmu_lock),
"%s called with kvm mmu_lock not held \n", __func__);
pte = __find_linux_pte(gp->shadow_pgtable, ea, NULL, hshift);
return pte;
}
static inline bool kvmhv_n_rmap_is_equal(u64 rmap_1, u64 rmap_2)
{
return !((rmap_1 ^ rmap_2) & (RMAP_NESTED_LPID_MASK |
RMAP_NESTED_GPA_MASK));
}
void kvmhv_insert_nest_rmap(struct kvm *kvm, unsigned long *rmapp,
struct rmap_nested **n_rmap)
{
struct llist_node *entry = ((struct llist_head *) rmapp)->first;
struct rmap_nested *cursor;
u64 rmap, new_rmap = (*n_rmap)->rmap;
/* Are there any existing entries? */
if (!(*rmapp)) {
/* No -> use the rmap as a single entry */
*rmapp = new_rmap | RMAP_NESTED_IS_SINGLE_ENTRY;
return;
}
/* Do any entries match what we're trying to insert? */
for_each_nest_rmap_safe(cursor, entry, &rmap) {
if (kvmhv_n_rmap_is_equal(rmap, new_rmap))
return;
}
/* Do we need to create a list or just add the new entry? */
rmap = *rmapp;
if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */
*rmapp = 0UL;
llist_add(&((*n_rmap)->list), (struct llist_head *) rmapp);
if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */
(*n_rmap)->list.next = (struct llist_node *) rmap;
/* Set NULL so not freed by caller */
*n_rmap = NULL;
}
static void kvmhv_update_nest_rmap_rc(struct kvm *kvm, u64 n_rmap,
unsigned long clr, unsigned long set,
unsigned long hpa, unsigned long mask)
{
unsigned long gpa;
unsigned int shift, lpid;
pte_t *ptep;
gpa = n_rmap & RMAP_NESTED_GPA_MASK;
lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
/* Find the pte */
ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
/*
* If the pte is present and the pfn is still the same, update the pte.
* If the pfn has changed then this is a stale rmap entry, the nested
* gpa actually points somewhere else now, and there is nothing to do.
* XXX A future optimisation would be to remove the rmap entry here.
*/
if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa)) {
__radix_pte_update(ptep, clr, set);
kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
}
}
/*
* For a given list of rmap entries, update the rc bits in all ptes in shadow
* page tables for nested guests which are referenced by the rmap list.
*/
void kvmhv_update_nest_rmap_rc_list(struct kvm *kvm, unsigned long *rmapp,
unsigned long clr, unsigned long set,
unsigned long hpa, unsigned long nbytes)
{
struct llist_node *entry = ((struct llist_head *) rmapp)->first;
struct rmap_nested *cursor;
unsigned long rmap, mask;
if ((clr | set) & ~(_PAGE_DIRTY | _PAGE_ACCESSED))
return;
mask = PTE_RPN_MASK & ~(nbytes - 1);
hpa &= mask;
for_each_nest_rmap_safe(cursor, entry, &rmap)
kvmhv_update_nest_rmap_rc(kvm, rmap, clr, set, hpa, mask);
}
static void kvmhv_remove_nest_rmap(struct kvm *kvm, u64 n_rmap,
unsigned long hpa, unsigned long mask)
{
struct kvm_nested_guest *gp;
unsigned long gpa;
unsigned int shift, lpid;
pte_t *ptep;
gpa = n_rmap & RMAP_NESTED_GPA_MASK;
lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
gp = kvmhv_find_nested(kvm, lpid);
if (!gp)
return;
/* Find and invalidate the pte */
ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
/* Don't spuriously invalidate ptes if the pfn has changed */
if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa))
kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
}
static void kvmhv_remove_nest_rmap_list(struct kvm *kvm, unsigned long *rmapp,
unsigned long hpa, unsigned long mask)
{
struct llist_node *entry = llist_del_all((struct llist_head *) rmapp);
struct rmap_nested *cursor;
unsigned long rmap;
for_each_nest_rmap_safe(cursor, entry, &rmap) {
kvmhv_remove_nest_rmap(kvm, rmap, hpa, mask);
kfree(cursor);
}
}
/* called with kvm->mmu_lock held */
void kvmhv_remove_nest_rmap_range(struct kvm *kvm,
const struct kvm_memory_slot *memslot,
unsigned long gpa, unsigned long hpa,
unsigned long nbytes)
{
unsigned long gfn, end_gfn;
unsigned long addr_mask;
if (!memslot)
return;
gfn = (gpa >> PAGE_SHIFT) - memslot->base_gfn;
end_gfn = gfn + (nbytes >> PAGE_SHIFT);
addr_mask = PTE_RPN_MASK & ~(nbytes - 1);
hpa &= addr_mask;
for (; gfn < end_gfn; gfn++) {
unsigned long *rmap = &memslot->arch.rmap[gfn];
kvmhv_remove_nest_rmap_list(kvm, rmap, hpa, addr_mask);
}
}
static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free)
{
unsigned long page;
for (page = 0; page < free->npages; page++) {
unsigned long rmap, *rmapp = &free->arch.rmap[page];
struct rmap_nested *cursor;
struct llist_node *entry;
entry = llist_del_all((struct llist_head *) rmapp);
for_each_nest_rmap_safe(cursor, entry, &rmap)
kfree(cursor);
}
}
static bool kvmhv_invalidate_shadow_pte(struct kvm_vcpu *vcpu,
struct kvm_nested_guest *gp,
long gpa, int *shift_ret)
{
struct kvm *kvm = vcpu->kvm;
bool ret = false;
pte_t *ptep;
int shift;
spin_lock(&kvm->mmu_lock);
ptep = find_kvm_nested_guest_pte(kvm, gp->l1_lpid, gpa, &shift);
if (!shift)
shift = PAGE_SHIFT;
if (ptep && pte_present(*ptep)) {
kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
ret = true;
}
spin_unlock(&kvm->mmu_lock);
if (shift_ret)
*shift_ret = shift;
return ret;
}
static inline int get_ric(unsigned int instr)
{
return (instr >> 18) & 0x3;
}
static inline int get_prs(unsigned int instr)
{
return (instr >> 17) & 0x1;
}
static inline int get_r(unsigned int instr)
{
return (instr >> 16) & 0x1;
}
static inline int get_lpid(unsigned long r_val)
{
return r_val & 0xffffffff;
}
static inline int get_is(unsigned long r_val)
{
return (r_val >> 10) & 0x3;
}
static inline int get_ap(unsigned long r_val)
{
return (r_val >> 5) & 0x7;
}
static inline long get_epn(unsigned long r_val)
{
return r_val >> 12;
}
static int kvmhv_emulate_tlbie_tlb_addr(struct kvm_vcpu *vcpu, int lpid,
int ap, long epn)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_nested_guest *gp;
long npages;
int shift, shadow_shift;
unsigned long addr;
shift = ap_to_shift(ap);
addr = epn << 12;
if (shift < 0)
/* Invalid ap encoding */
return -EINVAL;
addr &= ~((1UL << shift) - 1);
npages = 1UL << (shift - PAGE_SHIFT);
gp = kvmhv_get_nested(kvm, lpid, false);
if (!gp) /* No such guest -> nothing to do */
return 0;
mutex_lock(&gp->tlb_lock);
/* There may be more than one host page backing this single guest pte */
do {
kvmhv_invalidate_shadow_pte(vcpu, gp, addr, &shadow_shift);
npages -= 1UL << (shadow_shift - PAGE_SHIFT);
addr += 1UL << shadow_shift;
} while (npages > 0);
mutex_unlock(&gp->tlb_lock);
kvmhv_put_nested(gp);
return 0;
}
static void kvmhv_emulate_tlbie_lpid(struct kvm_vcpu *vcpu,
struct kvm_nested_guest *gp, int ric)
{
struct kvm *kvm = vcpu->kvm;
mutex_lock(&gp->tlb_lock);
switch (ric) {
case 0:
/* Invalidate TLB */
spin_lock(&kvm->mmu_lock);
kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable,
gp->shadow_lpid);
kvmhv_flush_lpid(gp->shadow_lpid);
spin_unlock(&kvm->mmu_lock);
break;
case 1:
/*
* Invalidate PWC
* We don't cache this -> nothing to do
*/
break;
case 2:
/* Invalidate TLB, PWC and caching of partition table entries */
kvmhv_flush_nested(gp);
break;
default:
break;
}
mutex_unlock(&gp->tlb_lock);
}
static void kvmhv_emulate_tlbie_all_lpid(struct kvm_vcpu *vcpu, int ric)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_nested_guest *gp;
int i;
spin_lock(&kvm->mmu_lock);
for (i = 0; i <= kvm->arch.max_nested_lpid; i++) {
gp = kvm->arch.nested_guests[i];
if (gp) {
spin_unlock(&kvm->mmu_lock);
kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
spin_lock(&kvm->mmu_lock);
}
}
spin_unlock(&kvm->mmu_lock);
}
static int kvmhv_emulate_priv_tlbie(struct kvm_vcpu *vcpu, unsigned int instr,
unsigned long rsval, unsigned long rbval)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_nested_guest *gp;
int r, ric, prs, is, ap;
int lpid;
long epn;
int ret = 0;
ric = get_ric(instr);
prs = get_prs(instr);
r = get_r(instr);
lpid = get_lpid(rsval);
is = get_is(rbval);
/*
* These cases are invalid and are not handled:
* r != 1 -> Only radix supported
* prs == 1 -> Not HV privileged
* ric == 3 -> No cluster bombs for radix
* is == 1 -> Partition scoped translations not associated with pid
* (!is) && (ric == 1 || ric == 2) -> Not supported by ISA
*/
if ((!r) || (prs) || (ric == 3) || (is == 1) ||
((!is) && (ric == 1 || ric == 2)))
return -EINVAL;
switch (is) {
case 0:
/*
* We know ric == 0
* Invalidate TLB for a given target address
*/
epn = get_epn(rbval);
ap = get_ap(rbval);
ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap, epn);
break;
case 2:
/* Invalidate matching LPID */
gp = kvmhv_get_nested(kvm, lpid, false);
if (gp) {
kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
kvmhv_put_nested(gp);
}
break;
case 3:
/* Invalidate ALL LPIDs */
kvmhv_emulate_tlbie_all_lpid(vcpu, ric);
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
/*
* This handles the H_TLB_INVALIDATE hcall.
* Parameters are (r4) tlbie instruction code, (r5) rS contents,
* (r6) rB contents.
*/
long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu)
{
int ret;
ret = kvmhv_emulate_priv_tlbie(vcpu, kvmppc_get_gpr(vcpu, 4),
kvmppc_get_gpr(vcpu, 5), kvmppc_get_gpr(vcpu, 6));
if (ret)
return H_PARAMETER;
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,
unsigned long n_gpa, unsigned long dsisr,
struct kvmppc_pte *gpte_p)
{
u64 fault_addr, flags = dsisr & DSISR_ISSTORE;
int ret;
ret = kvmppc_mmu_walk_radix_tree(vcpu, n_gpa, gpte_p, gp->l1_gr_to_hr,
&fault_addr);
if (ret) {
/* We didn't find a pte */
if (ret == -EINVAL) {
/* Unsupported mmu config */
flags |= DSISR_UNSUPP_MMU;
} else if (ret == -ENOENT) {
/* No translation found */
flags |= DSISR_NOHPTE;
} else if (ret == -EFAULT) {
/* Couldn't access L1 real address */
flags |= DSISR_PRTABLE_FAULT;
vcpu->arch.fault_gpa = fault_addr;
} else {
/* Unknown error */
return ret;
}
goto forward_to_l1;
} else {
/* We found a pte -> check permissions */
if (dsisr & DSISR_ISSTORE) {
/* Can we write? */
if (!gpte_p->may_write) {
flags |= DSISR_PROTFAULT;
goto forward_to_l1;
}
} else if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
/* Can we execute? */
if (!gpte_p->may_execute) {
flags |= SRR1_ISI_N_G_OR_CIP;
goto forward_to_l1;
}
} else {
/* Can we read? */
if (!gpte_p->may_read && !gpte_p->may_write) {
flags |= DSISR_PROTFAULT;
goto forward_to_l1;
}
}
}
return 0;
forward_to_l1:
vcpu->arch.fault_dsisr = flags;
if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
vcpu->arch.shregs.msr &= SRR1_MSR_BITS;
vcpu->arch.shregs.msr |= flags;
}
return RESUME_HOST;
}
static long kvmhv_handle_nested_set_rc(struct kvm_vcpu *vcpu,
struct kvm_nested_guest *gp,
unsigned long n_gpa,
struct kvmppc_pte gpte,
unsigned long dsisr)
{
struct kvm *kvm = vcpu->kvm;
bool writing = !!(dsisr & DSISR_ISSTORE);
u64 pgflags;
long ret;
/* Are the rc bits set in the L1 partition scoped pte? */
pgflags = _PAGE_ACCESSED;
if (writing)
pgflags |= _PAGE_DIRTY;
if (pgflags & ~gpte.rc)
return RESUME_HOST;
spin_lock(&kvm->mmu_lock);
/* Set the rc bit in the pte of our (L0) pgtable for the L1 guest */
ret = kvmppc_hv_handle_set_rc(kvm, false, writing,
gpte.raddr, kvm->arch.lpid);
if (!ret) {
ret = -EINVAL;
goto out_unlock;
}
/* Set the rc bit in the pte of the shadow_pgtable for the nest guest */
ret = kvmppc_hv_handle_set_rc(kvm, true, writing,
n_gpa, gp->l1_lpid);
if (!ret)
ret = -EINVAL;
else
ret = 0;
out_unlock:
spin_unlock(&kvm->mmu_lock);
return ret;
}
static inline int kvmppc_radix_level_to_shift(int level)
{
switch (level) {
case 2:
return PUD_SHIFT;
case 1:
return PMD_SHIFT;
default:
return PAGE_SHIFT;
}
}
static inline int kvmppc_radix_shift_to_level(int shift)
{
if (shift == PUD_SHIFT)
return 2;
if (shift == PMD_SHIFT)
return 1;
if (shift == PAGE_SHIFT)
return 0;
WARN_ON_ONCE(1);
return 0;
}
/* called with gp->tlb_lock held */
static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu,
struct kvm_nested_guest *gp)
{
struct kvm *kvm = vcpu->kvm;
struct kvm_memory_slot *memslot;
struct rmap_nested *n_rmap;
struct kvmppc_pte gpte;
pte_t pte, *pte_p;
unsigned long mmu_seq;
unsigned long dsisr = vcpu->arch.fault_dsisr;
unsigned long ea = vcpu->arch.fault_dar;
unsigned long *rmapp;
unsigned long n_gpa, gpa, gfn, perm = 0UL;
unsigned int shift, l1_shift, level;
bool writing = !!(dsisr & DSISR_ISSTORE);
bool kvm_ro = false;
long int ret;
if (!gp->l1_gr_to_hr) {
kvmhv_update_ptbl_cache(gp);
if (!gp->l1_gr_to_hr)
return RESUME_HOST;
}
/* Convert the nested guest real address into a L1 guest real address */
n_gpa = vcpu->arch.fault_gpa & ~0xF000000000000FFFULL;
if (!(dsisr & DSISR_PRTABLE_FAULT))
n_gpa |= ea & 0xFFF;
ret = kvmhv_translate_addr_nested(vcpu, gp, n_gpa, dsisr, &gpte);
/*
* If the hardware found a translation but we don't now have a usable
* translation in the l1 partition-scoped tree, remove the shadow pte
* and let the guest retry.
*/
if (ret == RESUME_HOST &&
(dsisr & (DSISR_PROTFAULT | DSISR_BADACCESS | DSISR_NOEXEC_OR_G |
DSISR_BAD_COPYPASTE)))
goto inval;
if (ret)
return ret;
/* Failed to set the reference/change bits */
if (dsisr & DSISR_SET_RC) {
ret = kvmhv_handle_nested_set_rc(vcpu, gp, n_gpa, gpte, dsisr);
if (ret == RESUME_HOST)
return ret;
if (ret)
goto inval;
dsisr &= ~DSISR_SET_RC;
if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
DSISR_PROTFAULT)))
return RESUME_GUEST;
}
/*
* We took an HISI or HDSI while we were running a nested guest which
* means we have no partition scoped translation for that. This means
* we need to insert a pte for the mapping into our shadow_pgtable.
*/
l1_shift = gpte.page_shift;
if (l1_shift < PAGE_SHIFT) {
/* We don't support l1 using a page size smaller than our own */
pr_err("KVM: L1 guest page shift (%d) less than our own (%d)\n",
l1_shift, PAGE_SHIFT);
return -EINVAL;
}
gpa = gpte.raddr;
gfn = gpa >> PAGE_SHIFT;
/* 1. Get the corresponding host memslot */
memslot = gfn_to_memslot(kvm, gfn);
if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS)) {
/* unusual error -> reflect to the guest as a DSI */
kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
return RESUME_GUEST;
}
/* passthrough of emulated MMIO case */
return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing);
}
if (memslot->flags & KVM_MEM_READONLY) {
if (writing) {
/* Give the guest a DSI */
kvmppc_core_queue_data_storage(vcpu, ea,
DSISR_ISSTORE | DSISR_PROTFAULT);
return RESUME_GUEST;
}
kvm_ro = true;
}
/* 2. Find the host pte for this L1 guest real address */
/* Used to check for invalidations in progress */
mmu_seq = kvm->mmu_notifier_seq;
smp_rmb();
/* See if can find translation in our partition scoped tables for L1 */
pte = __pte(0);
spin_lock(&kvm->mmu_lock);
pte_p = find_kvm_secondary_pte(kvm, gpa, &shift);
if (!shift)
shift = PAGE_SHIFT;
if (pte_p)
pte = *pte_p;
spin_unlock(&kvm->mmu_lock);
if (!pte_present(pte) || (writing && !(pte_val(pte) & _PAGE_WRITE))) {
/* No suitable pte found -> try to insert a mapping */
ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot,
writing, kvm_ro, &pte, &level);
if (ret == -EAGAIN)
return RESUME_GUEST;
else if (ret)
return ret;
shift = kvmppc_radix_level_to_shift(level);
}
/* Align gfn to the start of the page */
gfn = (gpa & ~((1UL << shift) - 1)) >> PAGE_SHIFT;
/* 3. Compute the pte we need to insert for nest_gpa -> host r_addr */
/* The permissions is the combination of the host and l1 guest ptes */
perm |= gpte.may_read ? 0UL : _PAGE_READ;
perm |= gpte.may_write ? 0UL : _PAGE_WRITE;
perm |= gpte.may_execute ? 0UL : _PAGE_EXEC;
/* Only set accessed/dirty (rc) bits if set in host and l1 guest ptes */
perm |= (gpte.rc & _PAGE_ACCESSED) ? 0UL : _PAGE_ACCESSED;
perm |= ((gpte.rc & _PAGE_DIRTY) && writing) ? 0UL : _PAGE_DIRTY;
pte = __pte(pte_val(pte) & ~perm);
/* What size pte can we insert? */
if (shift > l1_shift) {
u64 mask;
unsigned int actual_shift = PAGE_SHIFT;
if (PMD_SHIFT < l1_shift)
actual_shift = PMD_SHIFT;
mask = (1UL << shift) - (1UL << actual_shift);
pte = __pte(pte_val(pte) | (gpa & mask));
shift = actual_shift;
}
level = kvmppc_radix_shift_to_level(shift);
n_gpa &= ~((1UL << shift) - 1);
/* 4. Insert the pte into our shadow_pgtable */
n_rmap = kzalloc(sizeof(*n_rmap), GFP_KERNEL);
if (!n_rmap)
return RESUME_GUEST; /* Let the guest try again */
n_rmap->rmap = (n_gpa & RMAP_NESTED_GPA_MASK) |
(((unsigned long) gp->l1_lpid) << RMAP_NESTED_LPID_SHIFT);
rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
ret = kvmppc_create_pte(kvm, gp->shadow_pgtable, pte, n_gpa, level,
mmu_seq, gp->shadow_lpid, rmapp, &n_rmap);
kfree(n_rmap);
if (ret == -EAGAIN)
ret = RESUME_GUEST; /* Let the guest try again */
return ret;
inval:
kvmhv_invalidate_shadow_pte(vcpu, gp, n_gpa, NULL);
return RESUME_GUEST;
}
long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu)
{
struct kvm_nested_guest *gp = vcpu->arch.nested;
long int ret;
mutex_lock(&gp->tlb_lock);
ret = __kvmhv_nested_page_fault(vcpu, gp);
mutex_unlock(&gp->tlb_lock);
return ret;
}
int kvmhv_nested_next_lpid(struct kvm *kvm, int lpid)
{
int ret = -1;
spin_lock(&kvm->mmu_lock);
while (++lpid <= kvm->arch.max_nested_lpid) {
if (kvm->arch.nested_guests[lpid]) {
ret = lpid;
break;
}
}
spin_unlock(&kvm->mmu_lock);
return ret;
}
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