linux/arch/powerpc/kvm/book3s_pr_papr.c
Paul Mackerras ef1af2e296 KVM: PPC: Book3S PR: Take SRCU read lock around RTAS kvm_read_guest() call
This does for PR KVM what c9438092ca ("KVM: PPC: Book3S HV: Take SRCU
read lock around kvm_read_guest() call") did for HV KVM, that is,
eliminate a "suspicious rcu_dereference_check() usage!" warning by
taking the SRCU lock around the call to kvmppc_rtas_hcall().

It also fixes a return of RESUME_HOST to return EMULATE_FAIL instead,
since kvmppc_h_pr() is supposed to return EMULATE_* values.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Graf <agraf@suse.de>
2014-07-28 15:23:16 +02:00

374 lines
9.6 KiB
C

/*
* Copyright (C) 2011. Freescale Inc. All rights reserved.
*
* Authors:
* Alexander Graf <agraf@suse.de>
* Paul Mackerras <paulus@samba.org>
*
* Description:
*
* Hypercall handling for running PAPR guests in PR KVM on Book 3S
* processors.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*/
#include <linux/anon_inodes.h>
#include <asm/uaccess.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#define HPTE_SIZE 16 /* bytes per HPT entry */
static unsigned long get_pteg_addr(struct kvm_vcpu *vcpu, long pte_index)
{
struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
unsigned long pteg_addr;
pte_index <<= 4;
pte_index &= ((1 << ((vcpu_book3s->sdr1 & 0x1f) + 11)) - 1) << 7 | 0x70;
pteg_addr = vcpu_book3s->sdr1 & 0xfffffffffffc0000ULL;
pteg_addr |= pte_index;
return pteg_addr;
}
static int kvmppc_h_pr_enter(struct kvm_vcpu *vcpu)
{
long flags = kvmppc_get_gpr(vcpu, 4);
long pte_index = kvmppc_get_gpr(vcpu, 5);
__be64 pteg[2 * 8];
__be64 *hpte;
unsigned long pteg_addr, i;
long int ret;
i = pte_index & 7;
pte_index &= ~7UL;
pteg_addr = get_pteg_addr(vcpu, pte_index);
mutex_lock(&vcpu->kvm->arch.hpt_mutex);
copy_from_user(pteg, (void __user *)pteg_addr, sizeof(pteg));
hpte = pteg;
ret = H_PTEG_FULL;
if (likely((flags & H_EXACT) == 0)) {
for (i = 0; ; ++i) {
if (i == 8)
goto done;
if ((be64_to_cpu(*hpte) & HPTE_V_VALID) == 0)
break;
hpte += 2;
}
} else {
hpte += i * 2;
if (*hpte & HPTE_V_VALID)
goto done;
}
hpte[0] = cpu_to_be64(kvmppc_get_gpr(vcpu, 6));
hpte[1] = cpu_to_be64(kvmppc_get_gpr(vcpu, 7));
pteg_addr += i * HPTE_SIZE;
copy_to_user((void __user *)pteg_addr, hpte, HPTE_SIZE);
kvmppc_set_gpr(vcpu, 4, pte_index | i);
ret = H_SUCCESS;
done:
mutex_unlock(&vcpu->kvm->arch.hpt_mutex);
kvmppc_set_gpr(vcpu, 3, ret);
return EMULATE_DONE;
}
static int kvmppc_h_pr_remove(struct kvm_vcpu *vcpu)
{
unsigned long flags= kvmppc_get_gpr(vcpu, 4);
unsigned long pte_index = kvmppc_get_gpr(vcpu, 5);
unsigned long avpn = kvmppc_get_gpr(vcpu, 6);
unsigned long v = 0, pteg, rb;
unsigned long pte[2];
long int ret;
pteg = get_pteg_addr(vcpu, pte_index);
mutex_lock(&vcpu->kvm->arch.hpt_mutex);
copy_from_user(pte, (void __user *)pteg, sizeof(pte));
pte[0] = be64_to_cpu((__force __be64)pte[0]);
pte[1] = be64_to_cpu((__force __be64)pte[1]);
ret = H_NOT_FOUND;
if ((pte[0] & HPTE_V_VALID) == 0 ||
((flags & H_AVPN) && (pte[0] & ~0x7fUL) != avpn) ||
((flags & H_ANDCOND) && (pte[0] & avpn) != 0))
goto done;
copy_to_user((void __user *)pteg, &v, sizeof(v));
rb = compute_tlbie_rb(pte[0], pte[1], pte_index);
vcpu->arch.mmu.tlbie(vcpu, rb, rb & 1 ? true : false);
ret = H_SUCCESS;
kvmppc_set_gpr(vcpu, 4, pte[0]);
kvmppc_set_gpr(vcpu, 5, pte[1]);
done:
mutex_unlock(&vcpu->kvm->arch.hpt_mutex);
kvmppc_set_gpr(vcpu, 3, ret);
return EMULATE_DONE;
}
/* Request defs for kvmppc_h_pr_bulk_remove() */
#define H_BULK_REMOVE_TYPE 0xc000000000000000ULL
#define H_BULK_REMOVE_REQUEST 0x4000000000000000ULL
#define H_BULK_REMOVE_RESPONSE 0x8000000000000000ULL
#define H_BULK_REMOVE_END 0xc000000000000000ULL
#define H_BULK_REMOVE_CODE 0x3000000000000000ULL
#define H_BULK_REMOVE_SUCCESS 0x0000000000000000ULL
#define H_BULK_REMOVE_NOT_FOUND 0x1000000000000000ULL
#define H_BULK_REMOVE_PARM 0x2000000000000000ULL
#define H_BULK_REMOVE_HW 0x3000000000000000ULL
#define H_BULK_REMOVE_RC 0x0c00000000000000ULL
#define H_BULK_REMOVE_FLAGS 0x0300000000000000ULL
#define H_BULK_REMOVE_ABSOLUTE 0x0000000000000000ULL
#define H_BULK_REMOVE_ANDCOND 0x0100000000000000ULL
#define H_BULK_REMOVE_AVPN 0x0200000000000000ULL
#define H_BULK_REMOVE_PTEX 0x00ffffffffffffffULL
#define H_BULK_REMOVE_MAX_BATCH 4
static int kvmppc_h_pr_bulk_remove(struct kvm_vcpu *vcpu)
{
int i;
int paramnr = 4;
int ret = H_SUCCESS;
mutex_lock(&vcpu->kvm->arch.hpt_mutex);
for (i = 0; i < H_BULK_REMOVE_MAX_BATCH; i++) {
unsigned long tsh = kvmppc_get_gpr(vcpu, paramnr+(2*i));
unsigned long tsl = kvmppc_get_gpr(vcpu, paramnr+(2*i)+1);
unsigned long pteg, rb, flags;
unsigned long pte[2];
unsigned long v = 0;
if ((tsh & H_BULK_REMOVE_TYPE) == H_BULK_REMOVE_END) {
break; /* Exit success */
} else if ((tsh & H_BULK_REMOVE_TYPE) !=
H_BULK_REMOVE_REQUEST) {
ret = H_PARAMETER;
break; /* Exit fail */
}
tsh &= H_BULK_REMOVE_PTEX | H_BULK_REMOVE_FLAGS;
tsh |= H_BULK_REMOVE_RESPONSE;
if ((tsh & H_BULK_REMOVE_ANDCOND) &&
(tsh & H_BULK_REMOVE_AVPN)) {
tsh |= H_BULK_REMOVE_PARM;
kvmppc_set_gpr(vcpu, paramnr+(2*i), tsh);
ret = H_PARAMETER;
break; /* Exit fail */
}
pteg = get_pteg_addr(vcpu, tsh & H_BULK_REMOVE_PTEX);
copy_from_user(pte, (void __user *)pteg, sizeof(pte));
pte[0] = be64_to_cpu((__force __be64)pte[0]);
pte[1] = be64_to_cpu((__force __be64)pte[1]);
/* tsl = AVPN */
flags = (tsh & H_BULK_REMOVE_FLAGS) >> 26;
if ((pte[0] & HPTE_V_VALID) == 0 ||
((flags & H_AVPN) && (pte[0] & ~0x7fUL) != tsl) ||
((flags & H_ANDCOND) && (pte[0] & tsl) != 0)) {
tsh |= H_BULK_REMOVE_NOT_FOUND;
} else {
/* Splat the pteg in (userland) hpt */
copy_to_user((void __user *)pteg, &v, sizeof(v));
rb = compute_tlbie_rb(pte[0], pte[1],
tsh & H_BULK_REMOVE_PTEX);
vcpu->arch.mmu.tlbie(vcpu, rb, rb & 1 ? true : false);
tsh |= H_BULK_REMOVE_SUCCESS;
tsh |= (pte[1] & (HPTE_R_C | HPTE_R_R)) << 43;
}
kvmppc_set_gpr(vcpu, paramnr+(2*i), tsh);
}
mutex_unlock(&vcpu->kvm->arch.hpt_mutex);
kvmppc_set_gpr(vcpu, 3, ret);
return EMULATE_DONE;
}
static int kvmppc_h_pr_protect(struct kvm_vcpu *vcpu)
{
unsigned long flags = kvmppc_get_gpr(vcpu, 4);
unsigned long pte_index = kvmppc_get_gpr(vcpu, 5);
unsigned long avpn = kvmppc_get_gpr(vcpu, 6);
unsigned long rb, pteg, r, v;
unsigned long pte[2];
long int ret;
pteg = get_pteg_addr(vcpu, pte_index);
mutex_lock(&vcpu->kvm->arch.hpt_mutex);
copy_from_user(pte, (void __user *)pteg, sizeof(pte));
pte[0] = be64_to_cpu((__force __be64)pte[0]);
pte[1] = be64_to_cpu((__force __be64)pte[1]);
ret = H_NOT_FOUND;
if ((pte[0] & HPTE_V_VALID) == 0 ||
((flags & H_AVPN) && (pte[0] & ~0x7fUL) != avpn))
goto done;
v = pte[0];
r = pte[1];
r &= ~(HPTE_R_PP0 | HPTE_R_PP | HPTE_R_N | HPTE_R_KEY_HI |
HPTE_R_KEY_LO);
r |= (flags << 55) & HPTE_R_PP0;
r |= (flags << 48) & HPTE_R_KEY_HI;
r |= flags & (HPTE_R_PP | HPTE_R_N | HPTE_R_KEY_LO);
pte[1] = r;
rb = compute_tlbie_rb(v, r, pte_index);
vcpu->arch.mmu.tlbie(vcpu, rb, rb & 1 ? true : false);
pte[0] = (__force u64)cpu_to_be64(pte[0]);
pte[1] = (__force u64)cpu_to_be64(pte[1]);
copy_to_user((void __user *)pteg, pte, sizeof(pte));
ret = H_SUCCESS;
done:
mutex_unlock(&vcpu->kvm->arch.hpt_mutex);
kvmppc_set_gpr(vcpu, 3, ret);
return EMULATE_DONE;
}
static int kvmppc_h_pr_put_tce(struct kvm_vcpu *vcpu)
{
unsigned long liobn = kvmppc_get_gpr(vcpu, 4);
unsigned long ioba = kvmppc_get_gpr(vcpu, 5);
unsigned long tce = kvmppc_get_gpr(vcpu, 6);
long rc;
rc = kvmppc_h_put_tce(vcpu, liobn, ioba, tce);
if (rc == H_TOO_HARD)
return EMULATE_FAIL;
kvmppc_set_gpr(vcpu, 3, rc);
return EMULATE_DONE;
}
static int kvmppc_h_pr_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd)
{
long rc = kvmppc_xics_hcall(vcpu, cmd);
kvmppc_set_gpr(vcpu, 3, rc);
return EMULATE_DONE;
}
int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd)
{
int rc, idx;
if (cmd <= MAX_HCALL_OPCODE &&
!test_bit(cmd/4, vcpu->kvm->arch.enabled_hcalls))
return EMULATE_FAIL;
switch (cmd) {
case H_ENTER:
return kvmppc_h_pr_enter(vcpu);
case H_REMOVE:
return kvmppc_h_pr_remove(vcpu);
case H_PROTECT:
return kvmppc_h_pr_protect(vcpu);
case H_BULK_REMOVE:
return kvmppc_h_pr_bulk_remove(vcpu);
case H_PUT_TCE:
return kvmppc_h_pr_put_tce(vcpu);
case H_CEDE:
kvmppc_set_msr_fast(vcpu, kvmppc_get_msr(vcpu) | MSR_EE);
kvm_vcpu_block(vcpu);
clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
vcpu->stat.halt_wakeup++;
return EMULATE_DONE;
case H_XIRR:
case H_CPPR:
case H_EOI:
case H_IPI:
case H_IPOLL:
case H_XIRR_X:
if (kvmppc_xics_enabled(vcpu))
return kvmppc_h_pr_xics_hcall(vcpu, cmd);
break;
case H_RTAS:
if (list_empty(&vcpu->kvm->arch.rtas_tokens))
break;
idx = srcu_read_lock(&vcpu->kvm->srcu);
rc = kvmppc_rtas_hcall(vcpu);
srcu_read_unlock(&vcpu->kvm->srcu, idx);
if (rc)
break;
kvmppc_set_gpr(vcpu, 3, 0);
return EMULATE_DONE;
}
return EMULATE_FAIL;
}
int kvmppc_hcall_impl_pr(unsigned long cmd)
{
switch (cmd) {
case H_ENTER:
case H_REMOVE:
case H_PROTECT:
case H_BULK_REMOVE:
case H_PUT_TCE:
case H_CEDE:
#ifdef CONFIG_KVM_XICS
case H_XIRR:
case H_CPPR:
case H_EOI:
case H_IPI:
case H_IPOLL:
case H_XIRR_X:
#endif
return 1;
}
return 0;
}
/*
* List of hcall numbers to enable by default.
* For compatibility with old userspace, we enable by default
* all hcalls that were implemented before the hcall-enabling
* facility was added. Note this list should not include H_RTAS.
*/
static unsigned int default_hcall_list[] = {
H_ENTER,
H_REMOVE,
H_PROTECT,
H_BULK_REMOVE,
H_PUT_TCE,
H_CEDE,
#ifdef CONFIG_KVM_XICS
H_XIRR,
H_CPPR,
H_EOI,
H_IPI,
H_IPOLL,
H_XIRR_X,
#endif
0
};
void kvmppc_pr_init_default_hcalls(struct kvm *kvm)
{
int i;
unsigned int hcall;
for (i = 0; default_hcall_list[i]; ++i) {
hcall = default_hcall_list[i];
WARN_ON(!kvmppc_hcall_impl_pr(hcall));
__set_bit(hcall / 4, kvm->arch.enabled_hcalls);
}
}