linux/arch/powerpc/kvm/book3s_xics.c
Paul Mackerras b1a4286b8f KVM: PPC: Book3S HV: Re-enable XICS fast path for irqfd-generated interrupts
Commit c9a5eccac1 ("kvm/eventfd: add arch-specific set_irq",
2015-10-16) added the possibility for architecture-specific code
to handle the generation of virtual interrupts in atomic context
where possible, without having to schedule a work function.

Since we can easily generate virtual interrupts on XICS without
having to do anything worse than take a spinlock, we define a
kvm_arch_set_irq_inatomic() for XICS.  We also remove kvm_set_msi()
since it is not used any more.

The one slightly tricky thing is that with the new interface, we
don't get told whether the interrupt is an MSI (or other edge
sensitive interrupt) vs. level-sensitive.  The difference as far
as interrupt generation is concerned is that for LSIs we have to
set the asserted flag so it will continue to fire until it is
explicitly cleared.

In fact the XICS code gets told which interrupts are LSIs by userspace
when it configures the interrupt via the KVM_DEV_XICS_GRP_SOURCES
attribute group on the XICS device.  To store this information, we add
a new "lsi" field to struct ics_irq_state.  With that we can also do a
better job of returning accurate values when reading the attribute
group.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2016-05-12 16:40:55 +10:00

1417 lines
35 KiB
C

/*
* 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 <linux/spinlock.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 <asm/time.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 spin lock protecting the information about the IRQ
* sources and avoiding simultaneous deliveries of 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);
/*
* Return value ideally indicates how the interrupt was handled, but no
* callers look at it (given that we don't implement KVM_IRQ_LINE_STATUS),
* so just return 0.
*/
static int ics_deliver_irq(struct kvmppc_xics *xics, u32 irq, u32 level)
{
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;
/*
* 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 == 1 && state->lsi) || level == KVM_INTERRUPT_SET_LEVEL)
state->asserted = 1;
else if (level == 0 || level == KVM_INTERRUPT_UNSET) {
state->asserted = 0;
return 0;
}
/* Attempt delivery */
icp_deliver_irq(xics, NULL, irq);
return 0;
}
static void ics_check_resend(struct kvmppc_xics *xics, struct kvmppc_ics *ics,
struct kvmppc_icp *icp)
{
int i;
unsigned long flags;
local_irq_save(flags);
arch_spin_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);
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
icp_deliver_irq(xics, icp, state->number);
local_irq_save(flags);
arch_spin_lock(&ics->lock);
}
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
}
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;
unsigned long flags;
local_irq_save(flags);
arch_spin_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;
}
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
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;
unsigned long flags;
if (!xics)
return -ENODEV;
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics)
return -EINVAL;
state = &ics->irq_state[src];
local_irq_save(flags);
arch_spin_lock(&ics->lock);
*server = state->server;
*priority = state->priority;
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
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 [%04lx] - 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 %#lx\n", irq, priority,
icp->server_num);
do {
old_state = new_state = READ_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;
unsigned long flags;
/*
* 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 */
local_irq_save(flags);
arch_spin_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 differentiate 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
* ics spin lock.
*
* 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) {
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
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) {
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
goto again;
}
}
out:
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
}
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 = READ_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 = READ_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.
*
* ICP state: Check_IPI
*
* If the CPPR is less favored, then we might be replacing
* an interrupt, and thus need to possibly reject it.
*
* ICP State: IPI
*
* Besides rejecting any pending interrupts, we also
* update XISR and pending_pri to mark IPI as pending.
*
* PAPR does not describe this state, but if the MFRR is being
* made less favored than its earlier value, there might be
* a previously-rejected interrupt needing to be resent.
* Ideally, we would want to resend only if
* prio(pending_interrupt) < mfrr &&
* prio(pending_interrupt) < cppr
* where pending interrupt is the one that was rejected. But
* we don't have that state, so we simply trigger a resend
* whenever the MFRR is made less favored.
*/
do {
old_state = new_state = READ_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) {
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 = READ_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 = READ_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);
kvm_notify_acked_irq(vcpu->kvm, 0, 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) {
icp->n_rm_kick_vcpu++;
kvmppc_fast_vcpu_kick(icp->rm_kick_target);
}
if (icp->rm_action & XICS_RM_CHECK_RESEND) {
icp->n_rm_check_resend++;
icp_check_resend(xics, icp->rm_resend_icp);
}
if (icp->rm_action & XICS_RM_REJECT) {
icp->n_rm_reject++;
icp_deliver_irq(xics, icp, icp->rm_reject);
}
if (icp->rm_action & XICS_RM_NOTIFY_EOI) {
icp->n_rm_notify_eoi++;
kvm_notify_acked_irq(vcpu->kvm, 0, icp->rm_eoied_irq);
}
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 && is_kvmppc_hv_enabled(vcpu->kvm))
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;
}
EXPORT_SYMBOL_GPL(kvmppc_xics_hcall);
/* -- 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;
unsigned long flags;
unsigned long t_rm_kick_vcpu, t_rm_check_resend;
unsigned long t_rm_reject, t_rm_notify_eoi;
unsigned long t_reject, t_check_resend;
if (!kvm)
return 0;
t_rm_kick_vcpu = 0;
t_rm_notify_eoi = 0;
t_rm_check_resend = 0;
t_rm_reject = 0;
t_check_resend = 0;
t_reject = 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 = READ_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);
t_rm_kick_vcpu += icp->n_rm_kick_vcpu;
t_rm_notify_eoi += icp->n_rm_notify_eoi;
t_rm_check_resend += icp->n_rm_check_resend;
t_rm_reject += icp->n_rm_reject;
t_check_resend += icp->n_check_resend;
t_reject += icp->n_reject;
}
seq_printf(m, "ICP Guest->Host totals: kick_vcpu=%lu check_resend=%lu reject=%lu notify_eoi=%lu\n",
t_rm_kick_vcpu, t_rm_check_resend,
t_rm_reject, t_rm_notify_eoi);
seq_printf(m, "ICP Real Mode totals: check_resend=%lu resend=%lu\n",
t_check_resend, t_reject);
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);
local_irq_save(flags);
arch_spin_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);
}
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
}
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;
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 = READ_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;
unsigned long flags;
ics = kvmppc_xics_find_ics(xics, irq, &idx);
if (!ics)
return -ENOENT;
irqp = &ics->irq_state[idx];
local_irq_save(flags);
arch_spin_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->lsi) {
val |= KVM_XICS_LEVEL_SENSITIVE;
if (irqp->asserted)
val |= KVM_XICS_PENDING;
} else if (irqp->masked_pending || irqp->resend)
val |= KVM_XICS_PENDING;
ret = 0;
}
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
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;
unsigned long flags;
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;
local_irq_save(flags);
arch_spin_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->lsi = 0;
irqp->asserted = 0;
if (val & KVM_XICS_LEVEL_SENSITIVE) {
irqp->lsi = 1;
if (val & KVM_XICS_PENDING)
irqp->asserted = 1;
}
irqp->exists = 1;
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
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);
}
int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *irq_entry,
struct kvm *kvm, int irq_source_id,
int level, bool line_status)
{
return kvm_set_irq(kvm, irq_source_id, irq_entry->gsi,
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) {
kfree(xics);
return ret;
}
xics_debugfs_init(xics);
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
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_HV_POSSIBLE */
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;
}
static int xics_set_irq(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int irq_source_id, int level,
bool line_status)
{
return kvm_set_irq(kvm, irq_source_id, e->gsi, level, line_status);
}
int kvm_irq_map_gsi(struct kvm *kvm,
struct kvm_kernel_irq_routing_entry *entries, int gsi)
{
entries->gsi = gsi;
entries->type = KVM_IRQ_ROUTING_IRQCHIP;
entries->set = xics_set_irq;
entries->irqchip.irqchip = 0;
entries->irqchip.pin = gsi;
return 1;
}
int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin)
{
return pin;
}