/*
* Copyright 2012 Michael Ellerman, IBM Corporation.
* Copyright 2012 Benjamin Herrenschmidt, IBM Corporation.
*
* 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/kernel.h>
#include <linux/kvm_host.h>
#include <linux/err.h>
#include <linux/gfp.h>
#include <linux/anon_inodes.h>
#include <asm/uaccess.h>
#include <asm/kvm_book3s.h>
#include <asm/kvm_ppc.h>
#include <asm/hvcall.h>
#include <asm/xics.h>
#include <asm/debug.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include "book3s_xics.h"
#if 1
#define XICS_DBG(fmt...) do { } while (0)
#else
#define XICS_DBG(fmt...) trace_printk(fmt)
#endif
#define ENABLE_REALMODE true
#define DEBUG_REALMODE false
/*
* LOCKING
* =======
*
* Each ICS has a mutex protecting the information about the IRQ
* sources and avoiding simultaneous deliveries if the same interrupt.
*
* ICP operations are done via a single compare & swap transaction
* (most ICP state fits in the union kvmppc_icp_state)
*/
/*
* TODO
* ====
*
* - To speed up resends, keep a bitmap of "resend" set bits in the
* ICS
*
* - Speed up server# -> ICP lookup (array ? hash table ?)
*
* - Make ICS lockless as well, or at least a per-interrupt lock or hashed
* locks array to improve scalability
*/
/* -- ICS routines -- */
static void icp_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
u32 new_irq);
static int ics_deliver_irq(struct kvmppc_xics *xics, u32 irq, u32 level,
bool report_status)
{
struct ics_irq_state *state;
struct kvmppc_ics *ics;
u16 src;
XICS_DBG("ics deliver %#x (level: %d)\n", irq, level);
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics) {
XICS_DBG("ics_deliver_irq: IRQ 0x%06x not found !\n", irq);
return -EINVAL;
}
state = &ics->irq_state[src];
if (!state->exists)
return -EINVAL;
if (report_status)
return state->asserted;
/*
* We set state->asserted locklessly. This should be fine as
* we are the only setter, thus concurrent access is undefined
* to begin with.
*/
if (level == KVM_INTERRUPT_SET_LEVEL)
state->asserted = 1;
else if (level == KVM_INTERRUPT_UNSET) {
state->asserted = 0;
return 0;
}
/* Attempt delivery */
icp_deliver_irq(xics, NULL, irq);
return state->asserted;
}
static void ics_check_resend(struct kvmppc_xics *xics, struct kvmppc_ics *ics,
struct kvmppc_icp *icp)
{
int i;
mutex_lock(&ics->lock);
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
struct ics_irq_state *state = &ics->irq_state[i];
if (!state->resend)
continue;
XICS_DBG("resend %#x prio %#x\n", state->number,
state->priority);
mutex_unlock(&ics->lock);
icp_deliver_irq(xics, icp, state->number);
mutex_lock(&ics->lock);
}
mutex_unlock(&ics->lock);
}
static bool write_xive(struct kvmppc_xics *xics, struct kvmppc_ics *ics,
struct ics_irq_state *state,
u32 server, u32 priority, u32 saved_priority)
{
bool deliver;
mutex_lock(&ics->lock);
state->server = server;
state->priority = priority;
state->saved_priority = saved_priority;
deliver = false;
if ((state->masked_pending || state->resend) && priority != MASKED) {
state->masked_pending = 0;
deliver = true;
}
mutex_unlock(&ics->lock);
return deliver;
}
int kvmppc_xics_set_xive(struct kvm *kvm, u32 irq, u32 server, u32 priority)
{
struct kvmppc_xics *xics = kvm->arch.xics;
struct kvmppc_icp *icp;
struct kvmppc_ics *ics;
struct ics_irq_state *state;
u16 src;
if (!xics)
return -ENODEV;
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics)
return -EINVAL;
state = &ics->irq_state[src];
icp = kvmppc_xics_find_server(kvm, server);
if (!icp)
return -EINVAL;
XICS_DBG("set_xive %#x server %#x prio %#x MP:%d RS:%d\n",
irq, server, priority,
state->masked_pending, state->resend);
if (write_xive(xics, ics, state, server, priority, priority))
icp_deliver_irq(xics, icp, irq);
return 0;
}
int kvmppc_xics_get_xive(struct kvm *kvm, u32 irq, u32 *server, u32 *priority)
{
struct kvmppc_xics *xics = kvm->arch.xics;
struct kvmppc_ics *ics;
struct ics_irq_state *state;
u16 src;
if (!xics)
return -ENODEV;
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics)
return -EINVAL;
state = &ics->irq_state[src];
mutex_lock(&ics->lock);
*server = state->server;
*priority = state->priority;
mutex_unlock(&ics->lock);
return 0;
}
int kvmppc_xics_int_on(struct kvm *kvm, u32 irq)
{
struct kvmppc_xics *xics = kvm->arch.xics;
struct kvmppc_icp *icp;
struct kvmppc_ics *ics;
struct ics_irq_state *state;
u16 src;
if (!xics)
return -ENODEV;
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics)
return -EINVAL;
state = &ics->irq_state[src];
icp = kvmppc_xics_find_server(kvm, state->server);
if (!icp)
return -EINVAL;
if (write_xive(xics, ics, state, state->server, state->saved_priority,
state->saved_priority))
icp_deliver_irq(xics, icp, irq);
return 0;
}
int kvmppc_xics_int_off(struct kvm *kvm, u32 irq)
{
struct kvmppc_xics *xics = kvm->arch.xics;
struct kvmppc_ics *ics;
struct ics_irq_state *state;
u16 src;
if (!xics)
return -ENODEV;
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics)
return -EINVAL;
state = &ics->irq_state[src];
write_xive(xics, ics, state, state->server, MASKED, state->priority);
return 0;
}
/* -- ICP routines, including hcalls -- */
static inline bool icp_try_update(struct kvmppc_icp *icp,
union kvmppc_icp_state old,
union kvmppc_icp_state new,
bool change_self)
{
bool success;
/* Calculate new output value */
new.out_ee = (new.xisr && (new.pending_pri < new.cppr));
/* Attempt atomic update */
success = cmpxchg64(&icp->state.raw, old.raw, new.raw) == old.raw;
if (!success)
goto bail;
XICS_DBG("UPD [%04x] - C:%02x M:%02x PP: %02x PI:%06x R:%d O:%d\n",
icp->server_num,
old.cppr, old.mfrr, old.pending_pri, old.xisr,
old.need_resend, old.out_ee);
XICS_DBG("UPD - C:%02x M:%02x PP: %02x PI:%06x R:%d O:%d\n",
new.cppr, new.mfrr, new.pending_pri, new.xisr,
new.need_resend, new.out_ee);
/*
* Check for output state update
*
* Note that this is racy since another processor could be updating
* the state already. This is why we never clear the interrupt output
* here, we only ever set it. The clear only happens prior to doing
* an update and only by the processor itself. Currently we do it
* in Accept (H_XIRR) and Up_Cppr (H_XPPR).
*
* We also do not try to figure out whether the EE state has changed,
* we unconditionally set it if the new state calls for it. The reason
* for that is that we opportunistically remove the pending interrupt
* flag when raising CPPR, so we need to set it back here if an
* interrupt is still pending.
*/
if (new.out_ee) {
kvmppc_book3s_queue_irqprio(icp->vcpu,
BOOK3S_INTERRUPT_EXTERNAL_LEVEL);
if (!change_self)
kvmppc_fast_vcpu_kick(icp->vcpu);
}
bail:
return success;
}
static void icp_check_resend(struct kvmppc_xics *xics,
struct kvmppc_icp *icp)
{
u32 icsid;
/* Order this load with the test for need_resend in the caller */
smp_rmb();
for_each_set_bit(icsid, icp->resend_map, xics->max_icsid + 1) {
struct kvmppc_ics *ics = xics->ics[icsid];
if (!test_and_clear_bit(icsid, icp->resend_map))
continue;
if (!ics)
continue;
ics_check_resend(xics, ics, icp);
}
}
static bool icp_try_to_deliver(struct kvmppc_icp *icp, u32 irq, u8 priority,
u32 *reject)
{
union kvmppc_icp_state old_state, new_state;
bool success;
XICS_DBG("try deliver %#x(P:%#x) to server %#x\n", irq, priority,
icp->server_num);
do {
old_state = new_state = ACCESS_ONCE(icp->state);
*reject = 0;
/* See if we can deliver */
success = new_state.cppr > priority &&
new_state.mfrr > priority &&
new_state.pending_pri > priority;
/*
* If we can, check for a rejection and perform the
* delivery
*/
if (success) {
*reject = new_state.xisr;
new_state.xisr = irq;
new_state.pending_pri = priority;
} else {
/*
* If we failed to deliver we set need_resend
* so a subsequent CPPR state change causes us
* to try a new delivery.
*/
new_state.need_resend = true;
}
} while (!icp_try_update(icp, old_state, new_state, false));
return success;
}
static void icp_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
u32 new_irq)
{
struct ics_irq_state *state;
struct kvmppc_ics *ics;
u32 reject;
u16 src;
/*
* This is used both for initial delivery of an interrupt and
* for subsequent rejection.
*
* Rejection can be racy vs. resends. We have evaluated the
* rejection in an atomic ICP transaction which is now complete,
* so potentially the ICP can already accept the interrupt again.
*
* So we need to retry the delivery. Essentially the reject path
* boils down to a failed delivery. Always.
*
* Now the interrupt could also have moved to a different target,
* thus we may need to re-do the ICP lookup as well
*/
again:
/* Get the ICS state and lock it */
ics = kvmppc_xics_find_ics(xics, new_irq, &src);
if (!ics) {
XICS_DBG("icp_deliver_irq: IRQ 0x%06x not found !\n", new_irq);
return;
}
state = &ics->irq_state[src];
/* Get a lock on the ICS */
mutex_lock(&ics->lock);
/* Get our server */
if (!icp || state->server != icp->server_num) {
icp = kvmppc_xics_find_server(xics->kvm, state->server);
if (!icp) {
pr_warn("icp_deliver_irq: IRQ 0x%06x server 0x%x not found !\n",
new_irq, state->server);
goto out;
}
}
/* Clear the resend bit of that interrupt */
state->resend = 0;
/*
* If masked, bail out
*
* Note: PAPR doesn't mention anything about masked pending
* when doing a resend, only when doing a delivery.
*
* However that would have the effect of losing a masked
* interrupt that was rejected and isn't consistent with
* the whole masked_pending business which is about not
* losing interrupts that occur while masked.
*
* I don't differenciate normal deliveries and resends, this
* implementation will differ from PAPR and not lose such
* interrupts.
*/
if (state->priority == MASKED) {
XICS_DBG("irq %#x masked pending\n", new_irq);
state->masked_pending = 1;
goto out;
}
/*
* Try the delivery, this will set the need_resend flag
* in the ICP as part of the atomic transaction if the
* delivery is not possible.
*
* Note that if successful, the new delivery might have itself
* rejected an interrupt that was "delivered" before we took the
* icp mutex.
*
* In this case we do the whole sequence all over again for the
* new guy. We cannot assume that the rejected interrupt is less
* favored than the new one, and thus doesn't need to be delivered,
* because by the time we exit icp_try_to_deliver() the target
* processor may well have alrady consumed & completed it, and thus
* the rejected interrupt might actually be already acceptable.
*/
if (icp_try_to_deliver(icp, new_irq, state->priority, &reject)) {
/*
* Delivery was successful, did we reject somebody else ?
*/
if (reject && reject != XICS_IPI) {
mutex_unlock(&ics->lock);
new_irq = reject;
goto again;
}
} else {
/*
* We failed to deliver the interrupt we need to set the
* resend map bit and mark the ICS state as needing a resend
*/
set_bit(ics->icsid, icp->resend_map);
state->resend = 1;
/*
* If the need_resend flag got cleared in the ICP some time
* between icp_try_to_deliver() atomic update and now, then
* we know it might have missed the resend_map bit. So we
* retry
*/
smp_mb();
if (!icp->state.need_resend) {
mutex_unlock(&ics->lock);
goto again;
}
}
out:
mutex_unlock(&ics->lock);
}
static void icp_down_cppr(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
u8 new_cppr)
{
union kvmppc_icp_state old_state, new_state;
bool resend;
/*
* This handles several related states in one operation:
*
* ICP State: Down_CPPR
*
* Load CPPR with new value and if the XISR is 0
* then check for resends:
*
* ICP State: Resend
*
* If MFRR is more favored than CPPR, check for IPIs
* and notify ICS of a potential resend. This is done
* asynchronously (when used in real mode, we will have
* to exit here).
*
* We do not handle the complete Check_IPI as documented
* here. In the PAPR, this state will be used for both
* Set_MFRR and Down_CPPR. However, we know that we aren't
* changing the MFRR state here so we don't need to handle
* the case of an MFRR causing a reject of a pending irq,
* this will have been handled when the MFRR was set in the
* first place.
*
* Thus we don't have to handle rejects, only resends.
*
* When implementing real mode for HV KVM, resend will lead to
* a H_TOO_HARD return and the whole transaction will be handled
* in virtual mode.
*/
do {
old_state = new_state = ACCESS_ONCE(icp->state);
/* Down_CPPR */
new_state.cppr = new_cppr;
/*
* Cut down Resend / Check_IPI / IPI
*
* The logic is that we cannot have a pending interrupt
* trumped by an IPI at this point (see above), so we
* know that either the pending interrupt is already an
* IPI (in which case we don't care to override it) or
* it's either more favored than us or non existent
*/
if (new_state.mfrr < new_cppr &&
new_state.mfrr <= new_state.pending_pri) {
WARN_ON(new_state.xisr != XICS_IPI &&
new_state.xisr != 0);
new_state.pending_pri = new_state.mfrr;
new_state.xisr = XICS_IPI;
}
/* Latch/clear resend bit */
resend = new_state.need_resend;
new_state.need_resend = 0;
} while (!icp_try_update(icp, old_state, new_state, true));
/*
* Now handle resend checks. Those are asynchronous to the ICP
* state update in HW (ie bus transactions) so we can handle them
* separately here too
*/
if (resend)
icp_check_resend(xics, icp);
}
static noinline unsigned long kvmppc_h_xirr(struct kvm_vcpu *vcpu)
{
union kvmppc_icp_state old_state, new_state;
struct kvmppc_icp *icp = vcpu->arch.icp;
u32 xirr;
/* First, remove EE from the processor */
kvmppc_book3s_dequeue_irqprio(icp->vcpu,
BOOK3S_INTERRUPT_EXTERNAL_LEVEL);
/*
* ICP State: Accept_Interrupt
*
* Return the pending interrupt (if any) along with the
* current CPPR, then clear the XISR & set CPPR to the
* pending priority
*/
do {
old_state = new_state = ACCESS_ONCE(icp->state);
xirr = old_state.xisr | (((u32)old_state.cppr) << 24);
if (!old_state.xisr)
break;
new_state.cppr = new_state.pending_pri;
new_state.pending_pri = 0xff;
new_state.xisr = 0;
} while (!icp_try_update(icp, old_state, new_state, true));
XICS_DBG("h_xirr vcpu %d xirr %#x\n", vcpu->vcpu_id, xirr);
return xirr;
}
static noinline int kvmppc_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
unsigned long mfrr)
{
union kvmppc_icp_state old_state, new_state;
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
struct kvmppc_icp *icp;
u32 reject;
bool resend;
bool local;
XICS_DBG("h_ipi vcpu %d to server %lu mfrr %#lx\n",
vcpu->vcpu_id, server, mfrr);
icp = vcpu->arch.icp;
local = icp->server_num == server;
if (!local) {
icp = kvmppc_xics_find_server(vcpu->kvm, server);
if (!icp)
return H_PARAMETER;
}
/*
* ICP state: Set_MFRR
*
* If the CPPR is more favored than the new MFRR, then
* nothing needs to be rejected as there can be no XISR to
* reject. If the MFRR is being made less favored then
* there might be a previously-rejected interrupt needing
* to be resent.
*
* If the CPPR is less favored, then we might be replacing
* an interrupt, and thus need to possibly reject it as in
*
* ICP state: Check_IPI
*/
do {
old_state = new_state = ACCESS_ONCE(icp->state);
/* Set_MFRR */
new_state.mfrr = mfrr;
/* Check_IPI */
reject = 0;
resend = false;
if (mfrr < new_state.cppr) {
/* Reject a pending interrupt if not an IPI */
if (mfrr <= new_state.pending_pri)
reject = new_state.xisr;
new_state.pending_pri = mfrr;
new_state.xisr = XICS_IPI;
}
if (mfrr > old_state.mfrr && mfrr > new_state.cppr) {
resend = new_state.need_resend;
new_state.need_resend = 0;
}
} while (!icp_try_update(icp, old_state, new_state, local));
/* Handle reject */
if (reject && reject != XICS_IPI)
icp_deliver_irq(xics, icp, reject);
/* Handle resend */
if (resend)
icp_check_resend(xics, icp);
return H_SUCCESS;
}
static int kvmppc_h_ipoll(struct kvm_vcpu *vcpu, unsigned long server)
{
union kvmppc_icp_state state;
struct kvmppc_icp *icp;
icp = vcpu->arch.icp;
if (icp->server_num != server) {
icp = kvmppc_xics_find_server(vcpu->kvm, server);
if (!icp)
return H_PARAMETER;
}
state = ACCESS_ONCE(icp->state);
kvmppc_set_gpr(vcpu, 4, ((u32)state.cppr << 24) | state.xisr);
kvmppc_set_gpr(vcpu, 5, state.mfrr);
return H_SUCCESS;
}
static noinline void kvmppc_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr)
{
union kvmppc_icp_state old_state, new_state;
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
struct kvmppc_icp *icp = vcpu->arch.icp;
u32 reject;
XICS_DBG("h_cppr vcpu %d cppr %#lx\n", vcpu->vcpu_id, cppr);
/*
* ICP State: Set_CPPR
*
* We can safely compare the new value with the current
* value outside of the transaction as the CPPR is only
* ever changed by the processor on itself
*/
if (cppr > icp->state.cppr)
icp_down_cppr(xics, icp, cppr);
else if (cppr == icp->state.cppr)
return;
/*
* ICP State: Up_CPPR
*
* The processor is raising its priority, this can result
* in a rejection of a pending interrupt:
*
* ICP State: Reject_Current
*
* We can remove EE from the current processor, the update
* transaction will set it again if needed
*/
kvmppc_book3s_dequeue_irqprio(icp->vcpu,
BOOK3S_INTERRUPT_EXTERNAL_LEVEL);
do {
old_state = new_state = ACCESS_ONCE(icp->state);
reject = 0;
new_state.cppr = cppr;
if (cppr <= new_state.pending_pri) {
reject = new_state.xisr;
new_state.xisr = 0;
new_state.pending_pri = 0xff;
}
} while (!icp_try_update(icp, old_state, new_state, true));
/*
* Check for rejects. They are handled by doing a new delivery
* attempt (see comments in icp_deliver_irq).
*/
if (reject && reject != XICS_IPI)
icp_deliver_irq(xics, icp, reject);
}
static noinline int kvmppc_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
{
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
struct kvmppc_icp *icp = vcpu->arch.icp;
struct kvmppc_ics *ics;
struct ics_irq_state *state;
u32 irq = xirr & 0x00ffffff;
u16 src;
XICS_DBG("h_eoi vcpu %d eoi %#lx\n", vcpu->vcpu_id, xirr);
/*
* ICP State: EOI
*
* Note: If EOI is incorrectly used by SW to lower the CPPR
* value (ie more favored), we do not check for rejection of
* a pending interrupt, this is a SW error and PAPR sepcifies
* that we don't have to deal with it.
*
* The sending of an EOI to the ICS is handled after the
* CPPR update
*
* ICP State: Down_CPPR which we handle
* in a separate function as it's shared with H_CPPR.
*/
icp_down_cppr(xics, icp, xirr >> 24);
/* IPIs have no EOI */
if (irq == XICS_IPI)
return H_SUCCESS;
/*
* EOI handling: If the interrupt is still asserted, we need to
* resend it. We can take a lockless "peek" at the ICS state here.
*
* "Message" interrupts will never have "asserted" set
*/
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics) {
XICS_DBG("h_eoi: IRQ 0x%06x not found !\n", irq);
return H_PARAMETER;
}
state = &ics->irq_state[src];
/* Still asserted, resend it */
if (state->asserted)
icp_deliver_irq(xics, icp, irq);
return H_SUCCESS;
}
static noinline int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall)
{
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
struct kvmppc_icp *icp = vcpu->arch.icp;
XICS_DBG("XICS_RM: H_%x completing, act: %x state: %lx tgt: %p\n",
hcall, icp->rm_action, icp->rm_dbgstate.raw, icp->rm_dbgtgt);
if (icp->rm_action & XICS_RM_KICK_VCPU)
kvmppc_fast_vcpu_kick(icp->rm_kick_target);
if (icp->rm_action & XICS_RM_CHECK_RESEND)
icp_check_resend(xics, icp);
if (icp->rm_action & XICS_RM_REJECT)
icp_deliver_irq(xics, icp, icp->rm_reject);
icp->rm_action = 0;
return H_SUCCESS;
}
int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
{
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
unsigned long res;
int rc = H_SUCCESS;
/* Check if we have an ICP */
if (!xics || !vcpu->arch.icp)
return H_HARDWARE;
/* These requests don't have real-mode implementations at present */
switch (req) {
case H_XIRR_X:
res = kvmppc_h_xirr(vcpu);
kvmppc_set_gpr(vcpu, 4, res);
kvmppc_set_gpr(vcpu, 5, get_tb());
return rc;
case H_IPOLL:
rc = kvmppc_h_ipoll(vcpu, kvmppc_get_gpr(vcpu, 4));
return rc;
}
/* Check for real mode returning too hard */
if (xics->real_mode)
return kvmppc_xics_rm_complete(vcpu, req);
switch (req) {
case H_XIRR:
res = kvmppc_h_xirr(vcpu);
kvmppc_set_gpr(vcpu, 4, res);
break;
case H_CPPR:
kvmppc_h_cppr(vcpu, kvmppc_get_gpr(vcpu, 4));
break;
case H_EOI:
rc = kvmppc_h_eoi(vcpu, kvmppc_get_gpr(vcpu, 4));
break;
case H_IPI:
rc = kvmppc_h_ipi(vcpu, kvmppc_get_gpr(vcpu, 4),
kvmppc_get_gpr(vcpu, 5));
break;
}
return rc;
}
/* -- Initialisation code etc. -- */
static int xics_debug_show(struct seq_file *m, void *private)
{
struct kvmppc_xics *xics = m->private;
struct kvm *kvm = xics->kvm;
struct kvm_vcpu *vcpu;
int icsid, i;
if (!kvm)
return 0;
seq_printf(m, "=========\nICP state\n=========\n");
kvm_for_each_vcpu(i, vcpu, kvm) {
struct kvmppc_icp *icp = vcpu->arch.icp;
union kvmppc_icp_state state;
if (!icp)
continue;
state.raw = ACCESS_ONCE(icp->state.raw);
seq_printf(m, "cpu server %#lx XIRR:%#x PPRI:%#x CPPR:%#x MFRR:%#x OUT:%d NR:%d\n",
icp->server_num, state.xisr,
state.pending_pri, state.cppr, state.mfrr,
state.out_ee, state.need_resend);
}
for (icsid = 0; icsid <= KVMPPC_XICS_MAX_ICS_ID; icsid++) {
struct kvmppc_ics *ics = xics->ics[icsid];
if (!ics)
continue;
seq_printf(m, "=========\nICS state for ICS 0x%x\n=========\n",
icsid);
mutex_lock(&ics->lock);
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
struct ics_irq_state *irq = &ics->irq_state[i];
seq_printf(m, "irq 0x%06x: server %#x prio %#x save prio %#x asserted %d resend %d masked pending %d\n",
irq->number, irq->server, irq->priority,
irq->saved_priority, irq->asserted,
irq->resend, irq->masked_pending);
}
mutex_unlock(&ics->lock);
}
return 0;
}
static int xics_debug_open(struct inode *inode, struct file *file)
{
return single_open(file, xics_debug_show, inode->i_private);
}
static const struct file_operations xics_debug_fops = {
.open = xics_debug_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static void xics_debugfs_init(struct kvmppc_xics *xics)
{
char *name;
name = kasprintf(GFP_KERNEL, "kvm-xics-%p", xics);
if (!name) {
pr_err("%s: no memory for name\n", __func__);
return;
}
xics->dentry = debugfs_create_file(name, S_IRUGO, powerpc_debugfs_root,
xics, &xics_debug_fops);
pr_debug("%s: created %s\n", __func__, name);
kfree(name);
}
static struct kvmppc_ics *kvmppc_xics_create_ics(struct kvm *kvm,
struct kvmppc_xics *xics, int irq)
{
struct kvmppc_ics *ics;
int i, icsid;
icsid = irq >> KVMPPC_XICS_ICS_SHIFT;
mutex_lock(&kvm->lock);
/* ICS already exists - somebody else got here first */
if (xics->ics[icsid])
goto out;
/* Create the ICS */
ics = kzalloc(sizeof(struct kvmppc_ics), GFP_KERNEL);
if (!ics)
goto out;
mutex_init(&ics->lock);
ics->icsid = icsid;
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
ics->irq_state[i].number = (icsid << KVMPPC_XICS_ICS_SHIFT) | i;
ics->irq_state[i].priority = MASKED;
ics->irq_state[i].saved_priority = MASKED;
}
smp_wmb();
xics->ics[icsid] = ics;
if (icsid > xics->max_icsid)
xics->max_icsid = icsid;
out:
mutex_unlock(&kvm->lock);
return xics->ics[icsid];
}
int kvmppc_xics_create_icp(struct kvm_vcpu *vcpu, unsigned long server_num)
{
struct kvmppc_icp *icp;
if (!vcpu->kvm->arch.xics)
return -ENODEV;
if (kvmppc_xics_find_server(vcpu->kvm, server_num))
return -EEXIST;
icp = kzalloc(sizeof(struct kvmppc_icp), GFP_KERNEL);
if (!icp)
return -ENOMEM;
icp->vcpu = vcpu;
icp->server_num = server_num;
icp->state.mfrr = MASKED;
icp->state.pending_pri = MASKED;
vcpu->arch.icp = icp;
XICS_DBG("created server for vcpu %d\n", vcpu->vcpu_id);
return 0;
}
u64 kvmppc_xics_get_icp(struct kvm_vcpu *vcpu)
{
struct kvmppc_icp *icp = vcpu->arch.icp;
union kvmppc_icp_state state;
if (!icp)
return 0;
state = icp->state;
return ((u64)state.cppr << KVM_REG_PPC_ICP_CPPR_SHIFT) |
((u64)state.xisr << KVM_REG_PPC_ICP_XISR_SHIFT) |
((u64)state.mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT) |
((u64)state.pending_pri << KVM_REG_PPC_ICP_PPRI_SHIFT);
}
int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval)
{
struct kvmppc_icp *icp = vcpu->arch.icp;
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
union kvmppc_icp_state old_state, new_state;
struct kvmppc_ics *ics;
u8 cppr, mfrr, pending_pri;
u32 xisr;
u16 src;
bool resend;
if (!icp || !xics)
return -ENOENT;
cppr = icpval >> KVM_REG_PPC_ICP_CPPR_SHIFT;
xisr = (icpval >> KVM_REG_PPC_ICP_XISR_SHIFT) &
KVM_REG_PPC_ICP_XISR_MASK;
mfrr = icpval >> KVM_REG_PPC_ICP_MFRR_SHIFT;
pending_pri = icpval >> KVM_REG_PPC_ICP_PPRI_SHIFT;
/* Require the new state to be internally consistent */
if (xisr == 0) {
if (pending_pri != 0xff)
return -EINVAL;
} else if (xisr == XICS_IPI) {
if (pending_pri != mfrr || pending_pri >= cppr)
return -EINVAL;
} else {
if (pending_pri >= mfrr || pending_pri >= cppr)
return -EINVAL;
ics = kvmppc_xics_find_ics(xics, xisr, &src);
if (!ics)
return -EINVAL;
}
new_state.raw = 0;
new_state.cppr = cppr;
new_state.xisr = xisr;
new_state.mfrr = mfrr;
new_state.pending_pri = pending_pri;
/*
* Deassert the CPU interrupt request.
* icp_try_update will reassert it if necessary.
*/
kvmppc_book3s_dequeue_irqprio(icp->vcpu,
BOOK3S_INTERRUPT_EXTERNAL_LEVEL);
/*
* Note that if we displace an interrupt from old_state.xisr,
* we don't mark it as rejected. We expect userspace to set
* the state of the interrupt sources to be consistent with
* the ICP states (either before or afterwards, which doesn't
* matter). We do handle resends due to CPPR becoming less
* favoured because that is necessary to end up with a
* consistent state in the situation where userspace restores
* the ICS states before the ICP states.
*/
do {
old_state = ACCESS_ONCE(icp->state);
if (new_state.mfrr <= old_state.mfrr) {
resend = false;
new_state.need_resend = old_state.need_resend;
} else {
resend = old_state.need_resend;
new_state.need_resend = 0;
}
} while (!icp_try_update(icp, old_state, new_state, false));
if (resend)
icp_check_resend(xics, icp);
return 0;
}
static int xics_get_source(struct kvmppc_xics *xics, long irq, u64 addr)
{
int ret;
struct kvmppc_ics *ics;
struct ics_irq_state *irqp;
u64 __user *ubufp = (u64 __user *) addr;
u16 idx;
u64 val, prio;
ics = kvmppc_xics_find_ics(xics, irq, &idx);
if (!ics)
return -ENOENT;
irqp = &ics->irq_state[idx];
mutex_lock(&ics->lock);
ret = -ENOENT;
if (irqp->exists) {
val = irqp->server;
prio = irqp->priority;
if (prio == MASKED) {
val |= KVM_XICS_MASKED;
prio = irqp->saved_priority;
}
val |= prio << KVM_XICS_PRIORITY_SHIFT;
if (irqp->asserted)
val |= KVM_XICS_LEVEL_SENSITIVE | KVM_XICS_PENDING;
else if (irqp->masked_pending || irqp->resend)
val |= KVM_XICS_PENDING;
ret = 0;
}
mutex_unlock(&ics->lock);
if (!ret && put_user(val, ubufp))
ret = -EFAULT;
return ret;
}
static int xics_set_source(struct kvmppc_xics *xics, long irq, u64 addr)
{
struct kvmppc_ics *ics;
struct ics_irq_state *irqp;
u64 __user *ubufp = (u64 __user *) addr;
u16 idx;
u64 val;
u8 prio;
u32 server;
if (irq < KVMPPC_XICS_FIRST_IRQ || irq >= KVMPPC_XICS_NR_IRQS)
return -ENOENT;
ics = kvmppc_xics_find_ics(xics, irq, &idx);
if (!ics) {
ics = kvmppc_xics_create_ics(xics->kvm, xics, irq);
if (!ics)
return -ENOMEM;
}
irqp = &ics->irq_state[idx];
if (get_user(val, ubufp))
return -EFAULT;
server = val & KVM_XICS_DESTINATION_MASK;
prio = val >> KVM_XICS_PRIORITY_SHIFT;
if (prio != MASKED &&
kvmppc_xics_find_server(xics->kvm, server) == NULL)
return -EINVAL;
mutex_lock(&ics->lock);
irqp->server = server;
irqp->saved_priority = prio;
if (val & KVM_XICS_MASKED)
prio = MASKED;
irqp->priority = prio;
irqp->resend = 0;
irqp->masked_pending = 0;
irqp->asserted = 0;
if ((val & KVM_XICS_PENDING) && (val & KVM_XICS_LEVEL_SENSITIVE))
irqp->asserted = 1;
irqp->exists = 1;
mutex_unlock(&ics->lock);
if (val & KVM_XICS_PENDING)
icp_deliver_irq(xics, NULL, irqp->number);
return 0;
}
int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
bool line_status)
{
struct kvmppc_xics *xics = kvm->arch.xics;
return ics_deliver_irq(xics, irq, level, line_status);
}
static int xics_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
struct kvmppc_xics *xics = dev->private;
switch (attr->group) {
case KVM_DEV_XICS_GRP_SOURCES:
return xics_set_source(xics, attr->attr, attr->addr);
}
return -ENXIO;
}
static int xics_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
struct kvmppc_xics *xics = dev->private;
switch (attr->group) {
case KVM_DEV_XICS_GRP_SOURCES:
return xics_get_source(xics, attr->attr, attr->addr);
}
return -ENXIO;
}
static int xics_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
switch (attr->group) {
case KVM_DEV_XICS_GRP_SOURCES:
if (attr->attr >= KVMPPC_XICS_FIRST_IRQ &&
attr->attr < KVMPPC_XICS_NR_IRQS)
return 0;
break;
}
return -ENXIO;
}
static void kvmppc_xics_free(struct kvm_device *dev)
{
struct kvmppc_xics *xics = dev->private;
int i;
struct kvm *kvm = xics->kvm;
debugfs_remove(xics->dentry);
if (kvm)
kvm->arch.xics = NULL;
for (i = 0; i <= xics->max_icsid; i++)
kfree(xics->ics[i]);
kfree(xics);
kfree(dev);
}
static int kvmppc_xics_create(struct kvm_device *dev, u32 type)
{
struct kvmppc_xics *xics;
struct kvm *kvm = dev->kvm;
int ret = 0;
xics = kzalloc(sizeof(*xics), GFP_KERNEL);
if (!xics)
return -ENOMEM;
dev->private = xics;
xics->dev = dev;
xics->kvm = kvm;
/* Already there ? */
mutex_lock(&kvm->lock);
if (kvm->arch.xics)
ret = -EEXIST;
else
kvm->arch.xics = xics;
mutex_unlock(&kvm->lock);
if (ret)
return ret;
xics_debugfs_init(xics);
#ifdef CONFIG_KVM_BOOK3S_64_HV
if (cpu_has_feature(CPU_FTR_ARCH_206)) {
/* Enable real mode support */
xics->real_mode = ENABLE_REALMODE;
xics->real_mode_dbg = DEBUG_REALMODE;
}
#endif /* CONFIG_KVM_BOOK3S_64_HV */
return 0;
}
struct kvm_device_ops kvm_xics_ops = {
.name = "kvm-xics",
.create = kvmppc_xics_create,
.destroy = kvmppc_xics_free,
.set_attr = xics_set_attr,
.get_attr = xics_get_attr,
.has_attr = xics_has_attr,
};
int kvmppc_xics_connect_vcpu(struct kvm_device *dev, struct kvm_vcpu *vcpu,
u32 xcpu)
{
struct kvmppc_xics *xics = dev->private;
int r = -EBUSY;
if (dev->ops != &kvm_xics_ops)
return -EPERM;
if (xics->kvm != vcpu->kvm)
return -EPERM;
if (vcpu->arch.irq_type)
return -EBUSY;
r = kvmppc_xics_create_icp(vcpu, xcpu);
if (!r)
vcpu->arch.irq_type = KVMPPC_IRQ_XICS;
return r;
}
void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu)
{
if (!vcpu->arch.icp)
return;
kfree(vcpu->arch.icp);
vcpu->arch.icp = NULL;
vcpu->arch.irq_type = KVMPPC_IRQ_DEFAULT;
}