* [PATCH v5 25/48] KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read
From: Nicholas Piggin @ 2021-04-01 15:03 UTC (permalink / raw)
To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
There is no need to save away the host DEC value, as it is derived
from the host timer subsystem, which maintains the next timer time.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/time.h | 5 +++++
arch/powerpc/kernel/time.c | 1 +
arch/powerpc/kvm/book3s_hv.c | 14 +++++++-------
3 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 68d94711811e..0128cd9769bc 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -101,6 +101,11 @@ extern void __init time_init(void);
DECLARE_PER_CPU(u64, decrementers_next_tb);
+static inline u64 timer_get_next_tb(void)
+{
+ return __this_cpu_read(decrementers_next_tb);
+}
+
/* Convert timebase ticks to nanoseconds */
unsigned long long tb_to_ns(unsigned long long tb_ticks);
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index fc42594c8223..8b9b38a8ce57 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -109,6 +109,7 @@ struct clock_event_device decrementer_clockevent = {
EXPORT_SYMBOL(decrementer_clockevent);
DEFINE_PER_CPU(u64, decrementers_next_tb);
+EXPORT_SYMBOL_GPL(decrementers_next_tb);
static DEFINE_PER_CPU(struct clock_event_device, decrementers);
#define XSEC_PER_SEC (1024*1024)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 7afa2e7a2867..dc1232d2a198 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3697,16 +3697,15 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
unsigned long host_amr = mfspr(SPRN_AMR);
unsigned long host_fscr = mfspr(SPRN_FSCR);
s64 dec;
- u64 tb;
+ u64 tb, next_timer;
int trap, save_pmu;
- dec = mfspr(SPRN_DEC);
tb = mftb();
- if (dec < 0)
+ next_timer = timer_get_next_tb();
+ if (tb >= next_timer)
return BOOK3S_INTERRUPT_HV_DECREMENTER;
- local_paca->kvm_hstate.dec_expires = dec + tb;
- if (local_paca->kvm_hstate.dec_expires < time_limit)
- time_limit = local_paca->kvm_hstate.dec_expires;
+ if (next_timer < time_limit)
+ time_limit = next_timer;
vcpu->arch.ceded = 0;
@@ -3889,7 +3888,8 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
vc->entry_exit_map = 0x101;
vc->in_guest = 0;
- mtspr(SPRN_DEC, local_paca->kvm_hstate.dec_expires - mftb());
+ next_timer = timer_get_next_tb();
+ mtspr(SPRN_DEC, next_timer - mftb());
mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
kvmhv_load_host_pmu();
--
2.23.0
^ permalink raw reply related
* [PATCH v5 24/48] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC
From: Nicholas Piggin @ 2021-04-01 15:03 UTC (permalink / raw)
To: kvm-ppc; +Cc: Alexey Kardashevskiy, linuxppc-dev, Nicholas Piggin
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
On processors that don't suppress the HDEC exceptions when LPCR[HDICE]=0,
this could help reduce needless guest exits due to leftover exceptions on
entering the guest.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/time.h | 2 ++
arch/powerpc/kernel/time.c | 1 +
arch/powerpc/kvm/book3s_hv.c | 3 ++-
3 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 8dd3cdb25338..68d94711811e 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -18,6 +18,8 @@
#include <asm/vdso/timebase.h>
/* time.c */
+extern u64 decrementer_max;
+
extern unsigned long tb_ticks_per_jiffy;
extern unsigned long tb_ticks_per_usec;
extern unsigned long tb_ticks_per_sec;
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index b67d93a609a2..fc42594c8223 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -89,6 +89,7 @@ static struct clocksource clocksource_timebase = {
#define DECREMENTER_DEFAULT_MAX 0x7FFFFFFF
u64 decrementer_max = DECREMENTER_DEFAULT_MAX;
+EXPORT_SYMBOL_GPL(decrementer_max); /* for KVM HDEC */
static int decrementer_set_next_event(unsigned long evt,
struct clock_event_device *dev);
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index c249f77ea08c..7afa2e7a2867 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3669,7 +3669,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
vc->tb_offset_applied = 0;
}
- mtspr(SPRN_HDEC, 0x7fffffff);
+ /* HDEC must be at least as large as DEC, so decrementer_max fits */
+ mtspr(SPRN_HDEC, decrementer_max);
switch_mmu_to_host_radix(kvm, host_pidr);
--
2.23.0
^ permalink raw reply related
* [PATCH v5 23/48] KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest LPCR
From: Nicholas Piggin @ 2021-04-01 15:03 UTC (permalink / raw)
To: kvm-ppc; +Cc: Alexey Kardashevskiy, linuxppc-dev, Nicholas Piggin,
Fabiano Rosas
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
LPCR[HDICE]=0 suppresses hypervisor decrementer exceptions on some
processors, so it must be enabled before HDEC is set.
Rather than set it in the host LPCR then setting HDEC, move the HDEC
update to after the guest MMU context (including LPCR) is loaded.
There shouldn't be much concern with delaying HDEC by some 10s or 100s
of nanoseconds by setting it a bit later.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv.c | 19 +++++++------------
1 file changed, 7 insertions(+), 12 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index c45352fbc25d..c249f77ea08c 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3551,20 +3551,9 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
host_dawrx1 = mfspr(SPRN_DAWRX1);
}
- /*
- * P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
- * so set HDICE before writing HDEC.
- */
- mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
- isync();
-
hdec = time_limit - mftb();
- if (hdec < 0) {
- mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
- isync();
+ if (hdec < 0)
return BOOK3S_INTERRUPT_HV_DECREMENTER;
- }
- mtspr(SPRN_HDEC, hdec);
if (vc->tb_offset) {
u64 new_tb = mftb() + vc->tb_offset;
@@ -3610,6 +3599,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
+ /*
+ * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
+ * so set guest LPCR (with HDICE) before writing HDEC.
+ */
+ mtspr(SPRN_HDEC, hdec);
+
mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
--
2.23.0
^ permalink raw reply related
* [PATCH v5 22/48] KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc
Cc: Alexey Kardashevskiy, linuxppc-dev, Cédric Le Goater,
Nicholas Piggin
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
In the interest of minimising the amount of code that is run in
"real-mode", don't handle hcalls in real mode in the P9 path.
POWER8 and earlier are much more expensive to exit from HV real mode
and switch to host mode, because on those processors HV interrupts get
to the hypervisor with the MMU off, and the other threads in the core
need to be pulled out of the guest, and SLBs all need to be saved,
ERATs invalidated, and host SLB reloaded before the MMU is re-enabled
in host mode. Hash guests also require a lot of hcalls to run. The
XICS interrupt controller requires hcalls to run.
By contrast, POWER9 has independent thread switching, and in radix mode
the hypervisor is already in a host virtual memory mode when the HV
interrupt is taken. Radix + xive guests don't need hcalls to handle
interrupts or manage translations.
So it's much less important to handle hcalls in real mode in P9.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/kvm_ppc.h | 6 +++
arch/powerpc/kvm/book3s.c | 6 +++
arch/powerpc/kvm/book3s_hv.c | 70 +++++++++++++++++++++----
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 5 ++
arch/powerpc/kvm/book3s_xive.c | 64 ++++++++++++++++++++++
5 files changed, 140 insertions(+), 11 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 73b1ca5a6471..cbd8deba2e8a 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -129,6 +129,7 @@ extern void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu);
extern int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu);
extern int kvmppc_core_pending_dec(struct kvm_vcpu *vcpu);
extern void kvmppc_core_queue_machine_check(struct kvm_vcpu *vcpu, ulong flags);
+extern void kvmppc_core_queue_syscall(struct kvm_vcpu *vcpu);
extern void kvmppc_core_queue_program(struct kvm_vcpu *vcpu, ulong flags);
extern void kvmppc_core_queue_fpunavail(struct kvm_vcpu *vcpu);
extern void kvmppc_core_queue_vec_unavail(struct kvm_vcpu *vcpu);
@@ -607,6 +608,7 @@ extern void kvmppc_free_pimap(struct kvm *kvm);
extern int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall);
extern void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu);
extern int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd);
+extern int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req);
extern u64 kvmppc_xics_get_icp(struct kvm_vcpu *vcpu);
extern int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval);
extern int kvmppc_xics_connect_vcpu(struct kvm_device *dev,
@@ -639,6 +641,8 @@ static inline int kvmppc_xics_enabled(struct kvm_vcpu *vcpu)
static inline void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu) { }
static inline int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 cmd)
{ return 0; }
+static inline int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
+ { return 0; }
#endif
#ifdef CONFIG_KVM_XIVE
@@ -673,6 +677,7 @@ extern int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
int level, bool line_status);
extern void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu);
extern void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu);
+extern void kvmppc_xive_rearm_escalation(struct kvm_vcpu *vcpu);
static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
{
@@ -714,6 +719,7 @@ static inline int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 ir
int level, bool line_status) { return -ENODEV; }
static inline void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu) { }
static inline void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu) { }
+static inline void kvmppc_xive_rearm_escalation(struct kvm_vcpu *vcpu) { }
static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
{ return 0; }
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 44bf567b6589..1658f899e289 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -171,6 +171,12 @@ void kvmppc_core_queue_machine_check(struct kvm_vcpu *vcpu, ulong flags)
}
EXPORT_SYMBOL_GPL(kvmppc_core_queue_machine_check);
+void kvmppc_core_queue_syscall(struct kvm_vcpu *vcpu)
+{
+ kvmppc_inject_interrupt(vcpu, BOOK3S_INTERRUPT_SYSCALL, 0);
+}
+EXPORT_SYMBOL(kvmppc_core_queue_syscall);
+
void kvmppc_core_queue_program(struct kvm_vcpu *vcpu, ulong flags)
{
/* might as well deliver this straight away */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 2dc65d752f80..c45352fbc25d 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1142,12 +1142,13 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
}
/*
- * Handle H_CEDE in the nested virtualization case where we haven't
- * called the real-mode hcall handlers in book3s_hv_rmhandlers.S.
+ * Handle H_CEDE in the P9 path where we don't call the real-mode hcall
+ * handlers in book3s_hv_rmhandlers.S.
+ *
* This has to be done early, not in kvmppc_pseries_do_hcall(), so
* that the cede logic in kvmppc_run_single_vcpu() works properly.
*/
-static void kvmppc_nested_cede(struct kvm_vcpu *vcpu)
+static void kvmppc_cede(struct kvm_vcpu *vcpu)
{
vcpu->arch.shregs.msr |= MSR_EE;
vcpu->arch.ceded = 1;
@@ -1400,17 +1401,28 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
}
case BOOK3S_INTERRUPT_SYSCALL:
{
- /* hcall - punt to userspace */
int i;
- /* hypercall with MSR_PR has already been handled in rmode,
- * and never reaches here.
- */
+ if (unlikely(vcpu->arch.shregs.msr & MSR_PR)) {
+ /*
+ * Guest userspace executed sc 1, reflect it back as a
+ * syscall as it may be a PR KVM hcall.
+ */
+ kvmppc_core_queue_syscall(vcpu);
+ r = RESUME_GUEST;
+ break;
+ }
+ /*
+ * hcall - gather args and set exit_reason. This will next be
+ * handled by kvmppc_pseries_do_hcall which may be able to deal
+ * with it and resume guest, or may punt to userspace.
+ */
run->papr_hcall.nr = kvmppc_get_gpr(vcpu, 3);
for (i = 0; i < 9; ++i)
run->papr_hcall.args[i] = kvmppc_get_gpr(vcpu, 4 + i);
run->exit_reason = KVM_EXIT_PAPR_HCALL;
+ /* Should this only be set if pseries_do_hcall fails? */
vcpu->arch.hcall_needed = 1;
r = RESUME_HOST;
break;
@@ -3669,6 +3681,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
return trap;
}
+static inline bool hcall_is_xics(unsigned long req)
+{
+ return req == H_EOI || req == H_CPPR || req == H_IPI ||
+ req == H_IPOLL || req == H_XIRR || req == H_XIRR_X;
+}
+
/*
* Virtual-mode guest entry for POWER9 and later when the host and
* guest are both using the radix MMU. The LPIDR has already been set.
@@ -3780,15 +3798,36 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
/* H_CEDE has to be handled now, not later */
if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
kvmppc_get_gpr(vcpu, 3) == H_CEDE) {
- kvmppc_nested_cede(vcpu);
+ kvmppc_cede(vcpu);
kvmppc_set_gpr(vcpu, 3, 0);
trap = 0;
}
} else {
kvmppc_xive_push_vcpu(vcpu);
trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
+ if (trap == BOOK3S_INTERRUPT_SYSCALL && !vcpu->arch.nested &&
+ !(vcpu->arch.shregs.msr & MSR_PR)) {
+ unsigned long req = kvmppc_get_gpr(vcpu, 3);
+
+ /* H_CEDE has to be handled now, not later */
+ if (req == H_CEDE) {
+ kvmppc_cede(vcpu);
+ kvmppc_xive_rearm_escalation(vcpu); /* may un-cede */
+ kvmppc_set_gpr(vcpu, 3, 0);
+ trap = 0;
+
+ /* XICS hcalls must be handled before xive is pulled */
+ } else if (hcall_is_xics(req)) {
+ int ret;
+
+ ret = kvmppc_xive_xics_hcall(vcpu, req);
+ if (ret != H_TOO_HARD) {
+ kvmppc_set_gpr(vcpu, 3, ret);
+ trap = 0;
+ }
+ }
+ }
kvmppc_xive_pull_vcpu(vcpu);
-
}
vcpu->arch.slb_max = 0;
@@ -4448,8 +4487,17 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
else
r = kvmppc_run_vcpu(vcpu);
- if (run->exit_reason == KVM_EXIT_PAPR_HCALL &&
- !(vcpu->arch.shregs.msr & MSR_PR)) {
+ if (run->exit_reason == KVM_EXIT_PAPR_HCALL) {
+ if (WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_PR)) {
+ /*
+ * These should have been caught reflected
+ * into the guest by now. Final sanity check:
+ * don't allow userspace to execute hcalls in
+ * the hypervisor.
+ */
+ r = RESUME_GUEST;
+ continue;
+ }
trace_kvm_hcall_enter(vcpu);
r = kvmppc_pseries_do_hcall(vcpu);
trace_kvm_hcall_exit(vcpu, r);
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index c11597f815e4..2d0d14ed1d92 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1397,9 +1397,14 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
mr r4,r9
bge fast_guest_return
2:
+ /* If we came in through the P9 short path, no real mode hcalls */
+ lwz r0, STACK_SLOT_SHORT_PATH(r1)
+ cmpwi r0, 0
+ bne no_try_real
/* See if this is an hcall we can handle in real mode */
cmpwi r12,BOOK3S_INTERRUPT_SYSCALL
beq hcall_try_real_mode
+no_try_real:
/* Hypervisor doorbell - exit only if host IPI flag set */
cmpwi r12, BOOK3S_INTERRUPT_H_DOORBELL
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index 741bf1f4387a..24c07094651a 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -158,6 +158,40 @@ void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvmppc_xive_pull_vcpu);
+void kvmppc_xive_rearm_escalation(struct kvm_vcpu *vcpu)
+{
+ void __iomem *esc_vaddr = (void __iomem *)vcpu->arch.xive_esc_vaddr;
+
+ if (!esc_vaddr)
+ return;
+
+ /* we are using XIVE with single escalation */
+
+ if (vcpu->arch.xive_esc_on) {
+ /*
+ * If we still have a pending escalation, abort the cede,
+ * and we must set PQ to 10 rather than 00 so that we don't
+ * potentially end up with two entries for the escalation
+ * interrupt in the XIVE interrupt queue. In that case
+ * we also don't want to set xive_esc_on to 1 here in
+ * case we race with xive_esc_irq().
+ */
+ vcpu->arch.ceded = 0;
+ /*
+ * The escalation interrupts are special as we don't EOI them.
+ * There is no need to use the load-after-store ordering offset
+ * to set PQ to 10 as we won't use StoreEOI.
+ */
+ __raw_readq(esc_vaddr + XIVE_ESB_SET_PQ_10);
+ } else {
+ vcpu->arch.xive_esc_on = true;
+ mb();
+ __raw_readq(esc_vaddr + XIVE_ESB_SET_PQ_00);
+ }
+ mb();
+}
+EXPORT_SYMBOL_GPL(kvmppc_xive_rearm_escalation);
+
/*
* This is a simple trigger for a generic XIVE IRQ. This must
* only be called for interrupts that support a trigger page
@@ -2106,6 +2140,36 @@ static int kvmppc_xive_create(struct kvm_device *dev, u32 type)
return 0;
}
+int kvmppc_xive_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
+{
+ struct kvmppc_vcore *vc = vcpu->arch.vcore;
+
+ /* The VM should have configured XICS mode before doing XICS hcalls. */
+ if (!kvmppc_xics_enabled(vcpu))
+ return H_TOO_HARD;
+
+ switch (req) {
+ case H_XIRR:
+ return xive_vm_h_xirr(vcpu);
+ case H_CPPR:
+ return xive_vm_h_cppr(vcpu, kvmppc_get_gpr(vcpu, 4));
+ case H_EOI:
+ return xive_vm_h_eoi(vcpu, kvmppc_get_gpr(vcpu, 4));
+ case H_IPI:
+ return xive_vm_h_ipi(vcpu, kvmppc_get_gpr(vcpu, 4),
+ kvmppc_get_gpr(vcpu, 5));
+ case H_IPOLL:
+ return xive_vm_h_ipoll(vcpu, kvmppc_get_gpr(vcpu, 4));
+ case H_XIRR_X:
+ xive_vm_h_xirr(vcpu);
+ kvmppc_set_gpr(vcpu, 5, get_tb() + vc->tb_offset);
+ return H_SUCCESS;
+ }
+
+ return H_UNSUPPORTED;
+}
+EXPORT_SYMBOL_GPL(kvmppc_xive_xics_hcall);
+
int kvmppc_xive_debug_show_queues(struct seq_file *m, struct kvm_vcpu *vcpu)
{
struct kvmppc_xive_vcpu *xc = vcpu->arch.xive_vcpu;
--
2.23.0
^ permalink raw reply related
* [PATCH v5 21/48] KVM: PPC: Book3S HV P9: Move xive vcpu context management into kvmhv_p9_guest_entry
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: Alexey Kardashevskiy, linuxppc-dev, Nicholas Piggin
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
Move the xive management up so the low level register switching can be
pushed further down in a later patch. XIVE MMIO CI operations can run in
higher level code with machine checks, tracing, etc., available.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 6ca47f26a397..2dc65d752f80 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3598,15 +3598,11 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
- kvmppc_xive_push_vcpu(vcpu);
-
mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
trap = __kvmhv_vcpu_entry_p9(vcpu);
- kvmppc_xive_pull_vcpu(vcpu);
-
/* Advance host PURR/SPURR by the amount used by guest */
purr = mfspr(SPRN_PURR);
spurr = mfspr(SPRN_SPURR);
@@ -3789,7 +3785,10 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
trap = 0;
}
} else {
+ kvmppc_xive_push_vcpu(vcpu);
trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
+ kvmppc_xive_pull_vcpu(vcpu);
+
}
vcpu->arch.slb_max = 0;
--
2.23.0
^ permalink raw reply related
* [PATCH v5 20/48] KVM: PPC: Book3S HV P9: implement kvmppc_xive_pull_vcpu in C
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc
Cc: Alexey Kardashevskiy, linuxppc-dev, Cédric Le Goater,
Nicholas Piggin
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
This is more symmetric with kvmppc_xive_push_vcpu. The extra test in
the asm will go away in a later change.
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/kvm_ppc.h | 2 ++
arch/powerpc/kvm/book3s_hv.c | 2 ++
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 5 ++++
arch/powerpc/kvm/book3s_xive.c | 31 +++++++++++++++++++++++++
4 files changed, 40 insertions(+)
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 9531b1c1b190..73b1ca5a6471 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -672,6 +672,7 @@ extern int kvmppc_xive_set_icp(struct kvm_vcpu *vcpu, u64 icpval);
extern int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
int level, bool line_status);
extern void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu);
+extern void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu);
static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
{
@@ -712,6 +713,7 @@ static inline int kvmppc_xive_set_icp(struct kvm_vcpu *vcpu, u64 icpval) { retur
static inline int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
int level, bool line_status) { return -ENODEV; }
static inline void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu) { }
+static inline void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu) { }
static inline int kvmppc_xive_enabled(struct kvm_vcpu *vcpu)
{ return 0; }
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 3424b1bfa98e..6ca47f26a397 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3605,6 +3605,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
trap = __kvmhv_vcpu_entry_p9(vcpu);
+ kvmppc_xive_pull_vcpu(vcpu);
+
/* Advance host PURR/SPURR by the amount used by guest */
purr = mfspr(SPRN_PURR);
spurr = mfspr(SPRN_SPURR);
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 75405ef53238..c11597f815e4 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1442,6 +1442,11 @@ guest_exit_cont: /* r9 = vcpu, r12 = trap, r13 = paca */
bl kvmhv_accumulate_time
#endif
#ifdef CONFIG_KVM_XICS
+ /* If we came in through the P9 short path, xive pull is done in C */
+ lwz r0, STACK_SLOT_SHORT_PATH(r1)
+ cmpwi r0, 0
+ bne 1f
+
/* We are exiting, pull the VP from the XIVE */
lbz r0, VCPU_XIVE_PUSHED(r9)
cmpwi cr0, r0, 0
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index e7219b6f5f9a..741bf1f4387a 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -127,6 +127,37 @@ void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvmppc_xive_push_vcpu);
+/*
+ * Pull a vcpu's context from the XIVE on guest exit.
+ * This assumes we are in virtual mode (MMU on)
+ */
+void kvmppc_xive_pull_vcpu(struct kvm_vcpu *vcpu)
+{
+ void __iomem *tima = local_paca->kvm_hstate.xive_tima_virt;
+
+ if (!vcpu->arch.xive_pushed)
+ return;
+
+ /*
+ * Should not have been pushed if there is no tima
+ */
+ if (WARN_ON(!tima))
+ return;
+
+ eieio();
+ /* First load to pull the context, we ignore the value */
+ __raw_readl(tima + TM_SPC_PULL_OS_CTX);
+ /* Second load to recover the context state (Words 0 and 1) */
+ vcpu->arch.xive_saved_state.w01 = __raw_readq(tima + TM_QW1_OS);
+
+ /* Fixup some of the state for the next load */
+ vcpu->arch.xive_saved_state.lsmfb = 0;
+ vcpu->arch.xive_saved_state.ack = 0xff;
+ vcpu->arch.xive_pushed = 0;
+ eieio();
+}
+EXPORT_SYMBOL_GPL(kvmppc_xive_pull_vcpu);
+
/*
* This is a simple trigger for a generic XIVE IRQ. This must
* only be called for interrupts that support a trigger page
--
2.23.0
^ permalink raw reply related
* [PATCH v5 19/48] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: Alexey Kardashevskiy, linuxppc-dev, Nicholas Piggin
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
Switching the MMU from radix<->radix mode is tricky particularly as the
MMU can remain enabled and requires a certain sequence of SPR updates.
Move these together into their own functions.
This also includes the radix TLB check / flush because it's tied in to
MMU switching due to tlbiel getting LPID from LPIDR.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv.c | 66 +++++++++++++++++++++++-------------
1 file changed, 43 insertions(+), 23 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index ed77aff9cdb6..3424b1bfa98e 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3478,12 +3478,49 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc)
trace_kvmppc_run_core(vc, 1);
}
+static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
+{
+ struct kvmppc_vcore *vc = vcpu->arch.vcore;
+ struct kvm_nested_guest *nested = vcpu->arch.nested;
+ u32 lpid;
+
+ lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
+
+ /*
+ * All the isync()s are overkill but trivially follow the ISA
+ * requirements. Some can likely be replaced with justification
+ * comment for why they are not needed.
+ */
+ isync();
+ mtspr(SPRN_LPID, lpid);
+ isync();
+ mtspr(SPRN_LPCR, lpcr);
+ isync();
+ mtspr(SPRN_PID, vcpu->arch.pid);
+ isync();
+
+ /* TLBIEL must have LPIDR set, so set guest LPID before flushing. */
+ kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
+}
+
+static void switch_mmu_to_host_radix(struct kvm *kvm, u32 pid)
+{
+ isync();
+ mtspr(SPRN_PID, pid);
+ isync();
+ mtspr(SPRN_LPID, kvm->arch.host_lpid);
+ isync();
+ mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
+ isync();
+}
+
/*
* Load up hypervisor-mode registers on P9.
*/
static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
unsigned long lpcr)
{
+ struct kvm *kvm = vcpu->kvm;
struct kvmppc_vcore *vc = vcpu->arch.vcore;
s64 hdec;
u64 tb, purr, spurr;
@@ -3506,12 +3543,12 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
* P8 and P9 suppress the HDEC exception when LPCR[HDICE] = 0,
* so set HDICE before writing HDEC.
*/
- mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr | LPCR_HDICE);
+ mtspr(SPRN_LPCR, kvm->arch.host_lpcr | LPCR_HDICE);
isync();
hdec = time_limit - mftb();
if (hdec < 0) {
- mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
+ mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
isync();
return BOOK3S_INTERRUPT_HV_DECREMENTER;
}
@@ -3546,7 +3583,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
}
mtspr(SPRN_CIABR, vcpu->arch.ciabr);
mtspr(SPRN_IC, vcpu->arch.ic);
- mtspr(SPRN_PID, vcpu->arch.pid);
mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
(local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
@@ -3560,8 +3596,7 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
mtspr(SPRN_AMOR, ~0UL);
- mtspr(SPRN_LPCR, lpcr);
- isync();
+ switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
kvmppc_xive_push_vcpu(vcpu);
@@ -3600,7 +3635,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
mtspr(SPRN_DAWR1, host_dawr1);
mtspr(SPRN_DAWRX1, host_dawrx1);
}
- mtspr(SPRN_PID, host_pidr);
/*
* Since this is radix, do a eieio; tlbsync; ptesync sequence in
@@ -3615,9 +3649,6 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
if (cpu_has_feature(CPU_FTR_ARCH_31))
asm volatile(PPC_CP_ABORT);
- mtspr(SPRN_LPID, vcpu->kvm->arch.host_lpid); /* restore host LPID */
- isync();
-
vc->dpdes = mfspr(SPRN_DPDES);
vc->vtb = mfspr(SPRN_VTB);
mtspr(SPRN_DPDES, 0);
@@ -3634,7 +3665,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
}
mtspr(SPRN_HDEC, 0x7fffffff);
- mtspr(SPRN_LPCR, vcpu->kvm->arch.host_lpcr);
+
+ switch_mmu_to_host_radix(kvm, host_pidr);
return trap;
}
@@ -4167,7 +4199,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
{
struct kvm_run *run = vcpu->run;
int trap, r, pcpu;
- int srcu_idx, lpid;
+ int srcu_idx;
struct kvmppc_vcore *vc;
struct kvm *kvm = vcpu->kvm;
struct kvm_nested_guest *nested = vcpu->arch.nested;
@@ -4241,13 +4273,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
vc->vcore_state = VCORE_RUNNING;
trace_kvmppc_run_core(vc, 0);
- if (cpu_has_feature(CPU_FTR_HVMODE)) {
- lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
- mtspr(SPRN_LPID, lpid);
- isync();
- kvmppc_check_need_tlb_flush(kvm, pcpu, nested);
- }
-
guest_enter_irqoff();
srcu_idx = srcu_read_lock(&kvm->srcu);
@@ -4266,11 +4291,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit,
srcu_read_unlock(&kvm->srcu, srcu_idx);
- if (cpu_has_feature(CPU_FTR_HVMODE)) {
- mtspr(SPRN_LPID, kvm->arch.host_lpid);
- isync();
- }
-
set_irq_happened(trap);
kvmppc_set_host_core(pcpu);
--
2.23.0
^ permalink raw reply related
* [PATCH v5 18/48] KVM: PPC: Book3S 64: Minimise hcall handler calling convention differences
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: Alexey Kardashevskiy, linuxppc-dev, Nicholas Piggin
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
This sets up the same calling convention from interrupt entry to
KVM interrupt handler for system calls as exists for other interrupt
types.
This is a better API, it uses a save area rather than SPR, and it has
more registers free to use. Using a single common API helps maintain
it, and it becomes easier to use in C in a later patch.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 21 +++++++++++-
arch/powerpc/kvm/book3s_64_entry.S | 51 +++++++++++-----------------
2 files changed, 39 insertions(+), 33 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 115cf79f3e82..4615057681c3 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1892,8 +1892,27 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100)
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
TRAMP_REAL_BEGIN(kvm_hcall)
+ std r9,PACA_EXGEN+EX_R9(r13)
+ std r11,PACA_EXGEN+EX_R11(r13)
+ std r12,PACA_EXGEN+EX_R12(r13)
+ mfcr r9
mfctr r10
- SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
+ std r10,PACA_EXGEN+EX_R13(r13)
+ li r10,0
+ std r10,PACA_EXGEN+EX_CFAR(r13)
+ std r10,PACA_EXGEN+EX_CTR(r13)
+ /*
+ * Save the PPR (on systems that support it) before changing to
+ * HMT_MEDIUM. That allows the KVM code to save that value into the
+ * guest state (it is the guest's PPR value).
+ */
+BEGIN_FTR_SECTION
+ mfspr r10,SPRN_PPR
+ std r10,PACA_EXGEN+EX_PPR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+ HMT_MEDIUM
+
#ifdef CONFIG_RELOCATABLE
/*
* Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 0791eb2e3b81..82de3e99404f 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -11,40 +11,28 @@
* These are branched to from interrupt handlers in exception-64s.S which set
* IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero.
*/
+
+/*
+ * This is a hcall, so register convention is as
+ * Documentation/powerpc/papr_hcalls.rst.
+ *
+ * This may also be a syscall from PR-KVM userspace that is to be
+ * reflected to the PR guest kernel, so registers may be set up for
+ * a system call rather than hcall. We don't currently clobber
+ * anything here, but the 0xc00 handler has already clobbered CTR
+ * and CR0, so PR-KVM can not support a guest kernel that preserves
+ * those registers across its system calls.
+ *
+ * The state of registers is as kvmppc_interrupt, except CFAR is not
+ * saved, R13 is not in SCRATCH0, and R10 does not contain the trap.
+ */
.global kvmppc_hcall
.balign IFETCH_ALIGN_BYTES
kvmppc_hcall:
- /*
- * This is a hcall, so register convention is as
- * Documentation/powerpc/papr_hcalls.rst, with these additions:
- * R13 = PACA
- * guest R13 saved in SPRN_SCRATCH0
- * R10 = free
- * guest r10 saved in PACA_EXGEN
- *
- * This may also be a syscall from PR-KVM userspace that is to be
- * reflected to the PR guest kernel, so registers may be set up for
- * a system call rather than hcall. We don't currently clobber
- * anything here, but the 0xc00 handler has already clobbered CTR
- * and CR0, so PR-KVM can not support a guest kernel that preserves
- * those registers across its system calls.
- */
- /*
- * Save the PPR (on systems that support it) before changing to
- * HMT_MEDIUM. That allows the KVM code to save that value into the
- * guest state (it is the guest's PPR value).
- */
-BEGIN_FTR_SECTION
- mfspr r10,SPRN_PPR
- std r10,HSTATE_PPR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
- HMT_MEDIUM
- mfcr r10
- std r12,HSTATE_SCRATCH0(r13)
- sldi r12,r10,32
- ori r12,r12,0xc00
- ld r10,PACA_EXGEN+EX_R10(r13)
- b do_kvm_interrupt
+ ld r10,PACA_EXGEN+EX_R13(r13)
+ SET_SCRATCH0(r10)
+ li r10,0xc00
+ /* Now we look like kvmppc_interrupt */
/*
* KVM interrupt entry occurs after GEN_INT_ENTRY runs, and follows that
@@ -91,7 +79,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
ld r10,EX_R10(r11)
ld r11,EX_R11(r11)
-do_kvm_interrupt:
/*
* Hcalls and other interrupts come here after normalising register
* contents and save locations:
--
2.23.0
^ permalink raw reply related
* [PATCH v5 17/48] KVM: PPC: Book3S 64: move bad_host_intr check to HV handler
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: Alexey Kardashevskiy, linuxppc-dev, Nicholas Piggin
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
This is not used by PR KVM.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_64_entry.S | 4 ----
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 4 +++-
arch/powerpc/kvm/book3s_segment.S | 3 +++
3 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 30acbfbd1875..0791eb2e3b81 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -107,16 +107,12 @@ do_kvm_interrupt:
beq- .Lmaybe_skip
.Lno_skip:
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
- cmpwi r9,KVM_GUEST_MODE_HOST_HV
- beq kvmppc_bad_host_intr
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
cmpwi r9,KVM_GUEST_MODE_GUEST
- ld r9,HSTATE_SCRATCH2(r13)
beq kvmppc_interrupt_pr
#endif
b kvmppc_interrupt_hv
#else
- ld r9,HSTATE_SCRATCH2(r13)
b kvmppc_interrupt_pr
#endif
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index f976efb7e4a9..75405ef53238 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1265,6 +1265,7 @@ hdec_soon:
kvmppc_interrupt_hv:
/*
* Register contents:
+ * R9 = HSTATE_IN_GUEST
* R12 = (guest CR << 32) | interrupt vector
* R13 = PACA
* guest R12 saved in shadow VCPU SCRATCH0
@@ -1272,6 +1273,8 @@ kvmppc_interrupt_hv:
* guest R9 saved in HSTATE_SCRATCH2
*/
/* We're now back in the host but in guest MMU context */
+ cmpwi r9,KVM_GUEST_MODE_HOST_HV
+ beq kvmppc_bad_host_intr
li r9, KVM_GUEST_MODE_HOST_HV
stb r9, HSTATE_IN_GUEST(r13)
@@ -3272,7 +3275,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_P9_TM_HV_ASSIST)
* cfar is saved in HSTATE_CFAR(r13)
* ppr is saved in HSTATE_PPR(r13)
*/
-.global kvmppc_bad_host_intr
kvmppc_bad_host_intr:
/*
* Switch to the emergency stack, but start half-way down in
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S
index 1f492aa4c8d6..202046a83fc1 100644
--- a/arch/powerpc/kvm/book3s_segment.S
+++ b/arch/powerpc/kvm/book3s_segment.S
@@ -164,12 +164,15 @@ kvmppc_interrupt_pr:
/* 64-bit entry. Register usage at this point:
*
* SPRG_SCRATCH0 = guest R13
+ * R9 = HSTATE_IN_GUEST
* R12 = (guest CR << 32) | exit handler id
* R13 = PACA
* HSTATE.SCRATCH0 = guest R12
+ * HSTATE.SCRATCH2 = guest R9
*/
#ifdef CONFIG_PPC64
/* Match 32-bit entry */
+ ld r9,HSTATE_SCRATCH2(r13)
rotldi r12, r12, 32 /* Flip R12 halves for stw */
stw r12, HSTATE_SCRATCH1(r13) /* CR is now in the low half */
srdi r12, r12, 32 /* shift trap into low half */
--
2.23.0
^ permalink raw reply related
* [PATCH v5 16/48] KVM: PPC: Book3S 64: Move interrupt early register setup to KVM
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
Like the earlier patch for hcalls, KVM interrupt entry requires a
different calling convention than the Linux interrupt handlers
set up. Move the code that converts from one to the other into KVM.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 131 +++++----------------------
arch/powerpc/kvm/book3s_64_entry.S | 50 +++++++++-
2 files changed, 71 insertions(+), 110 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index a23feaa445b5..115cf79f3e82 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -187,7 +187,6 @@ do_define_int n
.endif
.endm
-#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
/*
* All interrupts which set HSRR registers, as well as SRESET and MCE and
* syscall when invoked with "sc 1" switch to MSR[HV]=1 (HVMODE) to be taken,
@@ -220,54 +219,25 @@ do_define_int n
* to KVM to handle.
*/
-.macro KVMTEST name
+.macro KVMTEST name handler
+#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
lbz r10,HSTATE_IN_GUEST(r13)
cmpwi r10,0
- bne \name\()_kvm
-.endm
-
-.macro GEN_KVM name
- .balign IFETCH_ALIGN_BYTES
-\name\()_kvm:
-
-BEGIN_FTR_SECTION
- ld r10,IAREA+EX_CFAR(r13)
- std r10,HSTATE_CFAR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
-
- ld r10,IAREA+EX_CTR(r13)
- mtctr r10
-BEGIN_FTR_SECTION
- ld r10,IAREA+EX_PPR(r13)
- std r10,HSTATE_PPR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
- ld r11,IAREA+EX_R11(r13)
- ld r12,IAREA+EX_R12(r13)
- std r12,HSTATE_SCRATCH0(r13)
- sldi r12,r9,32
- ld r9,IAREA+EX_R9(r13)
- ld r10,IAREA+EX_R10(r13)
/* HSRR variants have the 0x2 bit added to their trap number */
.if IHSRR_IF_HVMODE
BEGIN_FTR_SECTION
- ori r12,r12,(IVEC + 0x2)
+ li r10,(IVEC + 0x2)
FTR_SECTION_ELSE
- ori r12,r12,(IVEC)
+ li r10,(IVEC)
ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
.elseif IHSRR
- ori r12,r12,(IVEC+ 0x2)
+ li r10,(IVEC + 0x2)
.else
- ori r12,r12,(IVEC)
+ li r10,(IVEC)
.endif
- b kvmppc_interrupt
-.endm
-
-#else
-.macro KVMTEST name
-.endm
-.macro GEN_KVM name
-.endm
+ bne \handler
#endif
+.endm
/*
* This is the BOOK3S interrupt entry code macro.
@@ -409,7 +379,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
DEFINE_FIXED_SYMBOL(\name\()_common_real)
\name\()_common_real:
.if IKVM_REAL
- KVMTEST \name
+ KVMTEST \name kvm_interrupt
.endif
ld r10,PACAKMSR(r13) /* get MSR value for kernel */
@@ -432,7 +402,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
DEFINE_FIXED_SYMBOL(\name\()_common_virt)
\name\()_common_virt:
.if IKVM_VIRT
- KVMTEST \name
+ KVMTEST \name kvm_interrupt
1:
.endif
.endif /* IVIRT */
@@ -446,7 +416,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_virt)
DEFINE_FIXED_SYMBOL(\name\()_common_real)
\name\()_common_real:
.if IKVM_REAL
- KVMTEST \name
+ KVMTEST \name kvm_interrupt
.endif
.endm
@@ -967,8 +937,6 @@ EXC_COMMON_BEGIN(system_reset_common)
EXCEPTION_RESTORE_REGS
RFI_TO_USER_OR_KERNEL
- GEN_KVM system_reset
-
/**
* Interrupt 0x200 - Machine Check Interrupt (MCE).
@@ -1132,7 +1100,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
/*
* Check if we are coming from guest. If yes, then run the normal
* exception handler which will take the
- * machine_check_kvm->kvmppc_interrupt branch to deliver the MC event
+ * machine_check_kvm->kvm_interrupt branch to deliver the MC event
* to guest.
*/
lbz r11,HSTATE_IN_GUEST(r13)
@@ -1203,8 +1171,6 @@ EXC_COMMON_BEGIN(machine_check_common)
bl machine_check_exception
b interrupt_return
- GEN_KVM machine_check
-
#ifdef CONFIG_PPC_P7_NAP
/*
@@ -1339,8 +1305,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
REST_NVGPRS(r1)
b interrupt_return
- GEN_KVM data_access
-
/**
* Interrupt 0x380 - Data Segment Interrupt (DSLB).
@@ -1390,8 +1354,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
bl do_bad_slb_fault
b interrupt_return
- GEN_KVM data_access_slb
-
/**
* Interrupt 0x400 - Instruction Storage Interrupt (ISI).
@@ -1428,8 +1390,6 @@ MMU_FTR_SECTION_ELSE
ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
b interrupt_return
- GEN_KVM instruction_access
-
/**
* Interrupt 0x480 - Instruction Segment Interrupt (ISLB).
@@ -1474,8 +1434,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
bl do_bad_slb_fault
b interrupt_return
- GEN_KVM instruction_access_slb
-
/**
* Interrupt 0x500 - External Interrupt.
@@ -1521,8 +1479,6 @@ EXC_COMMON_BEGIN(hardware_interrupt_common)
bl do_IRQ
b interrupt_return
- GEN_KVM hardware_interrupt
-
/**
* Interrupt 0x600 - Alignment Interrupt
@@ -1550,8 +1506,6 @@ EXC_COMMON_BEGIN(alignment_common)
REST_NVGPRS(r1) /* instruction emulation may change GPRs */
b interrupt_return
- GEN_KVM alignment
-
/**
* Interrupt 0x700 - Program Interrupt (program check).
@@ -1659,8 +1613,6 @@ EXC_COMMON_BEGIN(program_check_common)
REST_NVGPRS(r1) /* instruction emulation may change GPRs */
b interrupt_return
- GEN_KVM program_check
-
/*
* Interrupt 0x800 - Floating-Point Unavailable Interrupt.
@@ -1710,8 +1662,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_TM)
b interrupt_return
#endif
- GEN_KVM fp_unavailable
-
/**
* Interrupt 0x900 - Decrementer Interrupt.
@@ -1751,8 +1701,6 @@ EXC_COMMON_BEGIN(decrementer_common)
bl timer_interrupt
b interrupt_return
- GEN_KVM decrementer
-
/**
* Interrupt 0x980 - Hypervisor Decrementer Interrupt.
@@ -1798,8 +1746,6 @@ EXC_COMMON_BEGIN(hdecrementer_common)
ld r13,PACA_EXGEN+EX_R13(r13)
HRFI_TO_KERNEL
- GEN_KVM hdecrementer
-
/**
* Interrupt 0xa00 - Directed Privileged Doorbell Interrupt.
@@ -1840,8 +1786,6 @@ EXC_COMMON_BEGIN(doorbell_super_common)
#endif
b interrupt_return
- GEN_KVM doorbell_super
-
EXC_REAL_NONE(0xb00, 0x100)
EXC_VIRT_NONE(0x4b00, 0x100)
@@ -1891,7 +1835,7 @@ INT_DEFINE_END(system_call)
GET_PACA(r13)
std r10,PACA_EXGEN+EX_R10(r13)
INTERRUPT_TO_KERNEL
- KVMTEST system_call /* uses r10, branch to system_call_kvm */
+ KVMTEST system_call kvm_hcall /* uses r10, branch to kvm_hcall */
mfctr r9
#else
mr r9,r13
@@ -1947,7 +1891,7 @@ EXC_VIRT_BEGIN(system_call, 0x4c00, 0x100)
EXC_VIRT_END(system_call, 0x4c00, 0x100)
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
-TRAMP_REAL_BEGIN(system_call_kvm)
+TRAMP_REAL_BEGIN(kvm_hcall)
mfctr r10
SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
#ifdef CONFIG_RELOCATABLE
@@ -1987,8 +1931,6 @@ EXC_COMMON_BEGIN(single_step_common)
bl single_step_exception
b interrupt_return
- GEN_KVM single_step
-
/**
* Interrupt 0xe00 - Hypervisor Data Storage Interrupt (HDSI).
@@ -2027,8 +1969,6 @@ MMU_FTR_SECTION_ELSE
ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_TYPE_RADIX)
b interrupt_return
- GEN_KVM h_data_storage
-
/**
* Interrupt 0xe20 - Hypervisor Instruction Storage Interrupt (HISI).
@@ -2054,8 +1994,6 @@ EXC_COMMON_BEGIN(h_instr_storage_common)
bl unknown_exception
b interrupt_return
- GEN_KVM h_instr_storage
-
/**
* Interrupt 0xe40 - Hypervisor Emulation Assistance Interrupt.
@@ -2080,8 +2018,6 @@ EXC_COMMON_BEGIN(emulation_assist_common)
REST_NVGPRS(r1) /* instruction emulation may change GPRs */
b interrupt_return
- GEN_KVM emulation_assist
-
/**
* Interrupt 0xe60 - Hypervisor Maintenance Interrupt (HMI).
@@ -2153,8 +2089,6 @@ EXC_COMMON_BEGIN(hmi_exception_early_common)
EXCEPTION_RESTORE_REGS hsrr=1
GEN_INT_ENTRY hmi_exception, virt=0
- GEN_KVM hmi_exception_early
-
EXC_COMMON_BEGIN(hmi_exception_common)
GEN_COMMON hmi_exception
FINISH_NAP
@@ -2162,8 +2096,6 @@ EXC_COMMON_BEGIN(hmi_exception_common)
bl handle_hmi_exception
b interrupt_return
- GEN_KVM hmi_exception
-
/**
* Interrupt 0xe80 - Directed Hypervisor Doorbell Interrupt.
@@ -2195,8 +2127,6 @@ EXC_COMMON_BEGIN(h_doorbell_common)
#endif
b interrupt_return
- GEN_KVM h_doorbell
-
/**
* Interrupt 0xea0 - Hypervisor Virtualization Interrupt.
@@ -2224,8 +2154,6 @@ EXC_COMMON_BEGIN(h_virt_irq_common)
bl do_IRQ
b interrupt_return
- GEN_KVM h_virt_irq
-
EXC_REAL_NONE(0xec0, 0x20)
EXC_VIRT_NONE(0x4ec0, 0x20)
@@ -2270,8 +2198,6 @@ EXC_COMMON_BEGIN(performance_monitor_common)
bl performance_monitor_exception
b interrupt_return
- GEN_KVM performance_monitor
-
/**
* Interrupt 0xf20 - Vector Unavailable Interrupt.
@@ -2321,8 +2247,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
bl altivec_unavailable_exception
b interrupt_return
- GEN_KVM altivec_unavailable
-
/**
* Interrupt 0xf40 - VSX Unavailable Interrupt.
@@ -2371,8 +2295,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
bl vsx_unavailable_exception
b interrupt_return
- GEN_KVM vsx_unavailable
-
/**
* Interrupt 0xf60 - Facility Unavailable Interrupt.
@@ -2401,8 +2323,6 @@ EXC_COMMON_BEGIN(facility_unavailable_common)
REST_NVGPRS(r1) /* instruction emulation may change GPRs */
b interrupt_return
- GEN_KVM facility_unavailable
-
/**
* Interrupt 0xf60 - Hypervisor Facility Unavailable Interrupt.
@@ -2431,8 +2351,6 @@ EXC_COMMON_BEGIN(h_facility_unavailable_common)
REST_NVGPRS(r1) /* XXX Shouldn't be necessary in practice */
b interrupt_return
- GEN_KVM h_facility_unavailable
-
EXC_REAL_NONE(0xfa0, 0x20)
EXC_VIRT_NONE(0x4fa0, 0x20)
@@ -2462,8 +2380,6 @@ EXC_COMMON_BEGIN(cbe_system_error_common)
bl cbe_system_error_exception
b interrupt_return
- GEN_KVM cbe_system_error
-
#else /* CONFIG_CBE_RAS */
EXC_REAL_NONE(0x1200, 0x100)
EXC_VIRT_NONE(0x5200, 0x100)
@@ -2489,8 +2405,6 @@ EXC_COMMON_BEGIN(instruction_breakpoint_common)
bl instruction_breakpoint_exception
b interrupt_return
- GEN_KVM instruction_breakpoint
-
EXC_REAL_NONE(0x1400, 0x100)
EXC_VIRT_NONE(0x5400, 0x100)
@@ -2611,8 +2525,6 @@ EXC_COMMON_BEGIN(denorm_exception_common)
bl unknown_exception
b interrupt_return
- GEN_KVM denorm_exception
-
#ifdef CONFIG_CBE_RAS
INT_DEFINE_BEGIN(cbe_maintenance)
@@ -2630,8 +2542,6 @@ EXC_COMMON_BEGIN(cbe_maintenance_common)
bl cbe_maintenance_exception
b interrupt_return
- GEN_KVM cbe_maintenance
-
#else /* CONFIG_CBE_RAS */
EXC_REAL_NONE(0x1600, 0x100)
EXC_VIRT_NONE(0x5600, 0x100)
@@ -2662,8 +2572,6 @@ EXC_COMMON_BEGIN(altivec_assist_common)
#endif
b interrupt_return
- GEN_KVM altivec_assist
-
#ifdef CONFIG_CBE_RAS
INT_DEFINE_BEGIN(cbe_thermal)
@@ -2681,8 +2589,6 @@ EXC_COMMON_BEGIN(cbe_thermal_common)
bl cbe_thermal_exception
b interrupt_return
- GEN_KVM cbe_thermal
-
#else /* CONFIG_CBE_RAS */
EXC_REAL_NONE(0x1800, 0x100)
EXC_VIRT_NONE(0x5800, 0x100)
@@ -2935,6 +2841,15 @@ TRAMP_REAL_BEGIN(rfscv_flush_fallback)
USE_TEXT_SECTION()
+#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
+kvm_interrupt:
+ /*
+ * The conditional branch in KVMTEST can't reach all the way,
+ * make a stub.
+ */
+ b kvmppc_interrupt
+#endif
+
_GLOBAL(do_uaccess_flush)
UACCESS_FLUSH_FIXUP_SECTION
nop
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 71043b36afc3..30acbfbd1875 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -44,15 +44,61 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
sldi r12,r10,32
ori r12,r12,0xc00
ld r10,PACA_EXGEN+EX_R10(r13)
+ b do_kvm_interrupt
+/*
+ * KVM interrupt entry occurs after GEN_INT_ENTRY runs, and follows that
+ * call convention:
+ *
+ * guest R9-R13, CTR, CFAR, PPR saved in PACA EX_xxx save area
+ * guest (H)DAR, (H)DSISR are also in the save area for relevant interrupts
+ * guest R13 also saved in SCRATCH0
+ * R13 = PACA
+ * R11 = (H)SRR0
+ * R12 = (H)SRR1
+ * R9 = guest CR
+ * PPR is set to medium
+ *
+ * With the addition for KVM:
+ * R10 = trap vector
+ */
.global kvmppc_interrupt
.balign IFETCH_ALIGN_BYTES
kvmppc_interrupt:
+ li r11,PACA_EXGEN
+ cmpdi r10,0x200
+ bgt+ 1f
+ li r11,PACA_EXMC
+ beq 1f
+ li r11,PACA_EXNMI
+1: add r11,r11,r13
+
+BEGIN_FTR_SECTION
+ ld r12,EX_CFAR(r11)
+ std r12,HSTATE_CFAR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
+ ld r12,EX_CTR(r11)
+ mtctr r12
+BEGIN_FTR_SECTION
+ ld r12,EX_PPR(r11)
+ std r12,HSTATE_PPR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+ ld r12,EX_R12(r11)
+ std r12,HSTATE_SCRATCH0(r13)
+ sldi r12,r9,32
+ or r12,r12,r10
+ ld r9,EX_R9(r11)
+ ld r10,EX_R10(r11)
+ ld r11,EX_R11(r11)
+
+do_kvm_interrupt:
/*
- * Register contents:
+ * Hcalls and other interrupts come here after normalising register
+ * contents and save locations:
+ *
* R12 = (guest CR << 32) | interrupt vector
* R13 = PACA
- * guest R12 saved in shadow VCPU SCRATCH0
+ * guest R12 saved in shadow HSTATE_SCRATCH0
* guest R13 saved in SPRN_SCRATCH0
*/
std r9,HSTATE_SCRATCH2(r13)
--
2.23.0
^ permalink raw reply related
* [PATCH v5 15/48] KVM: PPC: Book3S 64: Move hcall early register setup to KVM
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
System calls / hcalls have a different calling convention than
other interrupts, so there is code in the KVMTEST to massage these
into the same form as other interrupt handlers.
Move this work into the KVM hcall handler. This means teaching KVM
a little more about the low level interrupt handler setup, PACA save
areas, etc., although that's not obviously worse than the current
approach of coming up with an entirely different interrupt register
/ save convention.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/exception-64s.h | 13 ++++++++
arch/powerpc/kernel/exceptions-64s.S | 42 +-----------------------
arch/powerpc/kvm/book3s_64_entry.S | 30 +++++++++++++++++
3 files changed, 44 insertions(+), 41 deletions(-)
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index c1a8aac01cf9..bb6f78fcf981 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -35,6 +35,19 @@
/* PACA save area size in u64 units (exgen, exmc, etc) */
#define EX_SIZE 10
+/* PACA save area offsets */
+#define EX_R9 0
+#define EX_R10 8
+#define EX_R11 16
+#define EX_R12 24
+#define EX_R13 32
+#define EX_DAR 40
+#define EX_DSISR 48
+#define EX_CCR 52
+#define EX_CFAR 56
+#define EX_PPR 64
+#define EX_CTR 72
+
/*
* maximum recursive depth of MCE exceptions
*/
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 98bf73df0f57..a23feaa445b5 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -21,22 +21,6 @@
#include <asm/feature-fixups.h>
#include <asm/kup.h>
-/* PACA save area offsets (exgen, exmc, etc) */
-#define EX_R9 0
-#define EX_R10 8
-#define EX_R11 16
-#define EX_R12 24
-#define EX_R13 32
-#define EX_DAR 40
-#define EX_DSISR 48
-#define EX_CCR 52
-#define EX_CFAR 56
-#define EX_PPR 64
-#define EX_CTR 72
-.if EX_SIZE != 10
- .error "EX_SIZE is wrong"
-.endif
-
/*
* Following are fixed section helper macros.
*
@@ -1964,29 +1948,8 @@ EXC_VIRT_END(system_call, 0x4c00, 0x100)
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
TRAMP_REAL_BEGIN(system_call_kvm)
- /*
- * This is a hcall, so register convention is as above, with these
- * differences:
- * r13 = PACA
- * ctr = orig r13
- * orig r10 saved in PACA
- */
- /*
- * Save the PPR (on systems that support it) before changing to
- * HMT_MEDIUM. That allows the KVM code to save that value into the
- * guest state (it is the guest's PPR value).
- */
-BEGIN_FTR_SECTION
- mfspr r10,SPRN_PPR
- std r10,HSTATE_PPR(r13)
-END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
- HMT_MEDIUM
mfctr r10
- SET_SCRATCH0(r10)
- mfcr r10
- std r12,HSTATE_SCRATCH0(r13)
- sldi r12,r10,32
- ori r12,r12,0xc00
+ SET_SCRATCH0(r10) /* Save r13 in SCRATCH0 */
#ifdef CONFIG_RELOCATABLE
/*
* Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
@@ -1994,15 +1957,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
*/
__LOAD_FAR_HANDLER(r10, kvmppc_hcall)
mtctr r10
- ld r10,PACA_EXGEN+EX_R10(r13)
bctr
#else
- ld r10,PACA_EXGEN+EX_R10(r13)
b kvmppc_hcall
#endif
#endif
-
/**
* Interrupt 0xd00 - Trace Interrupt.
* This is a synchronous interrupt in response to instruction step or
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 5b177c6d495b..71043b36afc3 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -14,6 +14,36 @@
.global kvmppc_hcall
.balign IFETCH_ALIGN_BYTES
kvmppc_hcall:
+ /*
+ * This is a hcall, so register convention is as
+ * Documentation/powerpc/papr_hcalls.rst, with these additions:
+ * R13 = PACA
+ * guest R13 saved in SPRN_SCRATCH0
+ * R10 = free
+ * guest r10 saved in PACA_EXGEN
+ *
+ * This may also be a syscall from PR-KVM userspace that is to be
+ * reflected to the PR guest kernel, so registers may be set up for
+ * a system call rather than hcall. We don't currently clobber
+ * anything here, but the 0xc00 handler has already clobbered CTR
+ * and CR0, so PR-KVM can not support a guest kernel that preserves
+ * those registers across its system calls.
+ */
+ /*
+ * Save the PPR (on systems that support it) before changing to
+ * HMT_MEDIUM. That allows the KVM code to save that value into the
+ * guest state (it is the guest's PPR value).
+ */
+BEGIN_FTR_SECTION
+ mfspr r10,SPRN_PPR
+ std r10,HSTATE_PPR(r13)
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+ HMT_MEDIUM
+ mfcr r10
+ std r12,HSTATE_SCRATCH0(r13)
+ sldi r12,r10,32
+ ori r12,r12,0xc00
+ ld r10,PACA_EXGEN+EX_R10(r13)
.global kvmppc_interrupt
.balign IFETCH_ALIGN_BYTES
--
2.23.0
^ permalink raw reply related
* [PATCH v5 14/48] KVM: PPC: Book3S 64: add hcall interrupt handler
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: Fabiano Rosas, linuxppc-dev, Nicholas Piggin, Daniel Axtens
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
Add a separate hcall entry point. This can be used to deal with the
different calling convention.
Reviewed-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 6 +++---
arch/powerpc/kvm/book3s_64_entry.S | 6 +++++-
2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 16fbfde960e7..98bf73df0f57 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1989,16 +1989,16 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
ori r12,r12,0xc00
#ifdef CONFIG_RELOCATABLE
/*
- * Requires __LOAD_FAR_HANDLER beause kvmppc_interrupt lives
+ * Requires __LOAD_FAR_HANDLER beause kvmppc_hcall lives
* outside the head section.
*/
- __LOAD_FAR_HANDLER(r10, kvmppc_interrupt)
+ __LOAD_FAR_HANDLER(r10, kvmppc_hcall)
mtctr r10
ld r10,PACA_EXGEN+EX_R10(r13)
bctr
#else
ld r10,PACA_EXGEN+EX_R10(r13)
- b kvmppc_interrupt
+ b kvmppc_hcall
#endif
#endif
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index a99c5d9891c0..5b177c6d495b 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -8,9 +8,13 @@
#include <asm/reg.h>
/*
- * This is branched to from interrupt handlers in exception-64s.S which set
+ * These are branched to from interrupt handlers in exception-64s.S which set
* IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero.
*/
+.global kvmppc_hcall
+.balign IFETCH_ALIGN_BYTES
+kvmppc_hcall:
+
.global kvmppc_interrupt
.balign IFETCH_ALIGN_BYTES
kvmppc_interrupt:
--
2.23.0
^ permalink raw reply related
* [PATCH v5 13/48] KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: Fabiano Rosas, linuxppc-dev, Nicholas Piggin, Daniel Axtens
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
Move the GUEST_MODE_SKIP logic into KVM code. This is quite a KVM
internal detail that has no real need to be in common handlers.
Also add a comment explaining why this thing exists.
Reviewed-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 60 ----------------------------
arch/powerpc/kvm/book3s_64_entry.S | 52 +++++++++++++++++++++++-
2 files changed, 51 insertions(+), 61 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 162595af1ac7..16fbfde960e7 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -133,7 +133,6 @@ name:
#define IBRANCH_TO_COMMON .L_IBRANCH_TO_COMMON_\name\() /* ENTRY branch to common */
#define IREALMODE_COMMON .L_IREALMODE_COMMON_\name\() /* Common runs in realmode */
#define IMASK .L_IMASK_\name\() /* IRQ soft-mask bit */
-#define IKVM_SKIP .L_IKVM_SKIP_\name\() /* Generate KVM skip handler */
#define IKVM_REAL .L_IKVM_REAL_\name\() /* Real entry tests KVM */
#define __IKVM_REAL(name) .L_IKVM_REAL_ ## name
#define IKVM_VIRT .L_IKVM_VIRT_\name\() /* Virt entry tests KVM */
@@ -190,9 +189,6 @@ do_define_int n
.ifndef IMASK
IMASK=0
.endif
- .ifndef IKVM_SKIP
- IKVM_SKIP=0
- .endif
.ifndef IKVM_REAL
IKVM_REAL=0
.endif
@@ -250,15 +246,10 @@ do_define_int n
.balign IFETCH_ALIGN_BYTES
\name\()_kvm:
- .if IKVM_SKIP
- cmpwi r10,KVM_GUEST_MODE_SKIP
- beq 89f
- .else
BEGIN_FTR_SECTION
ld r10,IAREA+EX_CFAR(r13)
std r10,HSTATE_CFAR(r13)
END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
- .endif
ld r10,IAREA+EX_CTR(r13)
mtctr r10
@@ -285,27 +276,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
ori r12,r12,(IVEC)
.endif
b kvmppc_interrupt
-
- .if IKVM_SKIP
-89: mtocrf 0x80,r9
- ld r10,IAREA+EX_CTR(r13)
- mtctr r10
- ld r9,IAREA+EX_R9(r13)
- ld r10,IAREA+EX_R10(r13)
- ld r11,IAREA+EX_R11(r13)
- ld r12,IAREA+EX_R12(r13)
- .if IHSRR_IF_HVMODE
- BEGIN_FTR_SECTION
- b kvmppc_skip_Hinterrupt
- FTR_SECTION_ELSE
- b kvmppc_skip_interrupt
- ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
- .elseif IHSRR
- b kvmppc_skip_Hinterrupt
- .else
- b kvmppc_skip_interrupt
- .endif
- .endif
.endm
#else
@@ -1083,7 +1053,6 @@ INT_DEFINE_BEGIN(machine_check)
ISET_RI=0
IDAR=1
IDSISR=1
- IKVM_SKIP=1
IKVM_REAL=1
INT_DEFINE_END(machine_check)
@@ -1356,7 +1325,6 @@ INT_DEFINE_BEGIN(data_access)
IVEC=0x300
IDAR=1
IDSISR=1
- IKVM_SKIP=1
IKVM_REAL=1
INT_DEFINE_END(data_access)
@@ -1410,7 +1378,6 @@ ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_TYPE_RADIX)
INT_DEFINE_BEGIN(data_access_slb)
IVEC=0x380
IDAR=1
- IKVM_SKIP=1
IKVM_REAL=1
INT_DEFINE_END(data_access_slb)
@@ -2080,7 +2047,6 @@ INT_DEFINE_BEGIN(h_data_storage)
IHSRR=1
IDAR=1
IDSISR=1
- IKVM_SKIP=1
IKVM_REAL=1
IKVM_VIRT=1
INT_DEFINE_END(h_data_storage)
@@ -3024,32 +2990,6 @@ EXPORT_SYMBOL(do_uaccess_flush)
MASKED_INTERRUPT
MASKED_INTERRUPT hsrr=1
-#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
-kvmppc_skip_interrupt:
- /*
- * Here all GPRs are unchanged from when the interrupt happened
- * except for r13, which is saved in SPRG_SCRATCH0.
- */
- mfspr r13, SPRN_SRR0
- addi r13, r13, 4
- mtspr SPRN_SRR0, r13
- GET_SCRATCH0(r13)
- RFI_TO_KERNEL
- b .
-
-kvmppc_skip_Hinterrupt:
- /*
- * Here all GPRs are unchanged from when the interrupt happened
- * except for r13, which is saved in SPRG_SCRATCH0.
- */
- mfspr r13, SPRN_HSRR0
- addi r13, r13, 4
- mtspr SPRN_HSRR0, r13
- GET_SCRATCH0(r13)
- HRFI_TO_KERNEL
- b .
-#endif
-
/*
* Relocation-on interrupts: A subset of the interrupts can be delivered
* with IR=1/DR=1, if AIL==2 and MSR.HV won't be changed by delivering
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 7a039ea78f15..a99c5d9891c0 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -1,6 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0-only */
#include <asm/asm-offsets.h>
#include <asm/cache.h>
+#include <asm/exception-64s.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_book3s_asm.h>
#include <asm/ppc_asm.h>
@@ -20,9 +21,12 @@ kvmppc_interrupt:
* guest R12 saved in shadow VCPU SCRATCH0
* guest R13 saved in SPRN_SCRATCH0
*/
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
std r9,HSTATE_SCRATCH2(r13)
lbz r9,HSTATE_IN_GUEST(r13)
+ cmpwi r9,KVM_GUEST_MODE_SKIP
+ beq- .Lmaybe_skip
+.Lno_skip:
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
cmpwi r9,KVM_GUEST_MODE_HOST_HV
beq kvmppc_bad_host_intr
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
@@ -32,5 +36,51 @@ kvmppc_interrupt:
#endif
b kvmppc_interrupt_hv
#else
+ ld r9,HSTATE_SCRATCH2(r13)
b kvmppc_interrupt_pr
#endif
+
+/*
+ * KVM uses a trick where it is running in MSR[HV]=1 mode in real-mode with the
+ * guest MMU context loaded, and it sets KVM_GUEST_MODE_SKIP and enables
+ * MSR[DR]=1 while leaving MSR[IR]=0, so it continues to fetch HV instructions
+ * but loads and stores will access the guest context. This is used to load
+ * the faulting instruction without walking page tables.
+ *
+ * However the guest context may not be able to translate, or it may cause a
+ * machine check or other issue, which will result in a fault in the host
+ * (even with KVM-HV).
+ *
+ * These faults are caught here and if the fault was (or was likely) due to
+ * that load, then we just return with the PC advanced +4 and skip the load,
+ * which then goes to the slow path and walks the page tables.
+ */
+.Lmaybe_skip:
+ cmpwi r12,BOOK3S_INTERRUPT_MACHINE_CHECK
+ beq 1f
+ cmpwi r12,BOOK3S_INTERRUPT_DATA_STORAGE
+ beq 1f
+ cmpwi r12,BOOK3S_INTERRUPT_DATA_SEGMENT
+ beq 1f
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+ /* HSRR interrupts have 2 added to trap vector */
+ cmpwi r12,BOOK3S_INTERRUPT_H_DATA_STORAGE | 0x2
+ beq 2f
+#endif
+ b .Lno_skip
+1: mfspr r9,SPRN_SRR0
+ addi r9,r9,4
+ mtspr SPRN_SRR0,r9
+ ld r12,HSTATE_SCRATCH0(r13)
+ ld r9,HSTATE_SCRATCH2(r13)
+ GET_SCRATCH0(r13)
+ RFI_TO_KERNEL
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+2: mfspr r9,SPRN_HSRR0
+ addi r9,r9,4
+ mtspr SPRN_HSRR0,r9
+ ld r12,HSTATE_SCRATCH0(r13)
+ ld r9,HSTATE_SCRATCH2(r13)
+ GET_SCRATCH0(r13)
+ HRFI_TO_KERNEL
+#endif
--
2.23.0
^ permalink raw reply related
* [PATCH v5 12/48] KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: Fabiano Rosas, linuxppc-dev, Nicholas Piggin, Daniel Axtens
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
Rather than bifurcate the call depending on whether or not HV is
possible, and have the HV entry test for PR, just make a single
common point which does the demultiplexing. This makes it simpler
to add another type of exit handler.
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 8 +-----
arch/powerpc/kvm/Makefile | 3 +++
arch/powerpc/kvm/book3s_64_entry.S | 36 +++++++++++++++++++++++++
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 11 ++------
4 files changed, 42 insertions(+), 16 deletions(-)
create mode 100644 arch/powerpc/kvm/book3s_64_entry.S
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index c9c446ccff54..162595af1ac7 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -208,7 +208,6 @@ do_define_int n
.endm
#ifdef CONFIG_KVM_BOOK3S_64_HANDLER
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
/*
* All interrupts which set HSRR registers, as well as SRESET and MCE and
* syscall when invoked with "sc 1" switch to MSR[HV]=1 (HVMODE) to be taken,
@@ -238,13 +237,8 @@ do_define_int n
/*
* If an interrupt is taken while a guest is running, it is immediately routed
- * to KVM to handle. If both HV and PR KVM arepossible, KVM interrupts go first
- * to kvmppc_interrupt_hv, which handles the PR guest case.
+ * to KVM to handle.
*/
-#define kvmppc_interrupt kvmppc_interrupt_hv
-#else
-#define kvmppc_interrupt kvmppc_interrupt_pr
-#endif
.macro KVMTEST name
lbz r10,HSTATE_IN_GUEST(r13)
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 2bfeaa13befb..cdd119028f64 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -59,6 +59,9 @@ kvm-pr-y := \
kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
tm.o
+kvm-book3s_64-builtin-objs-y += \
+ book3s_64_entry.o
+
ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HANDLER) += \
book3s_rmhandlers.o
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
new file mode 100644
index 000000000000..7a039ea78f15
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#include <asm/asm-offsets.h>
+#include <asm/cache.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_book3s_asm.h>
+#include <asm/ppc_asm.h>
+#include <asm/reg.h>
+
+/*
+ * This is branched to from interrupt handlers in exception-64s.S which set
+ * IKVM_REAL or IKVM_VIRT, if HSTATE_IN_GUEST was found to be non-zero.
+ */
+.global kvmppc_interrupt
+.balign IFETCH_ALIGN_BYTES
+kvmppc_interrupt:
+ /*
+ * Register contents:
+ * R12 = (guest CR << 32) | interrupt vector
+ * R13 = PACA
+ * guest R12 saved in shadow VCPU SCRATCH0
+ * guest R13 saved in SPRN_SCRATCH0
+ */
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+ std r9,HSTATE_SCRATCH2(r13)
+ lbz r9,HSTATE_IN_GUEST(r13)
+ cmpwi r9,KVM_GUEST_MODE_HOST_HV
+ beq kvmppc_bad_host_intr
+#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
+ cmpwi r9,KVM_GUEST_MODE_GUEST
+ ld r9,HSTATE_SCRATCH2(r13)
+ beq kvmppc_interrupt_pr
+#endif
+ b kvmppc_interrupt_hv
+#else
+ b kvmppc_interrupt_pr
+#endif
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 5e634db4809b..f976efb7e4a9 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1269,16 +1269,8 @@ kvmppc_interrupt_hv:
* R13 = PACA
* guest R12 saved in shadow VCPU SCRATCH0
* guest R13 saved in SPRN_SCRATCH0
+ * guest R9 saved in HSTATE_SCRATCH2
*/
- std r9, HSTATE_SCRATCH2(r13)
- lbz r9, HSTATE_IN_GUEST(r13)
- cmpwi r9, KVM_GUEST_MODE_HOST_HV
- beq kvmppc_bad_host_intr
-#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
- cmpwi r9, KVM_GUEST_MODE_GUEST
- ld r9, HSTATE_SCRATCH2(r13)
- beq kvmppc_interrupt_pr
-#endif
/* We're now back in the host but in guest MMU context */
li r9, KVM_GUEST_MODE_HOST_HV
stb r9, HSTATE_IN_GUEST(r13)
@@ -3280,6 +3272,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_P9_TM_HV_ASSIST)
* cfar is saved in HSTATE_CFAR(r13)
* ppr is saved in HSTATE_PPR(r13)
*/
+.global kvmppc_bad_host_intr
kvmppc_bad_host_intr:
/*
* Switch to the emergency stack, but start half-way down in
--
2.23.0
^ permalink raw reply related
* [PATCH v5 11/48] KVM: PPC: Book3S HV: Ensure MSR[HV] is always clear in guest MSR
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
Rather than clear the HV bit from the MSR at guest entry, make it clear
that the hypervisor does not allow the guest to set the bit.
The HV clear is kept in guest entry for now, but a future patch will
warn if it is present.
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv_builtin.c | 4 ++--
arch/powerpc/kvm/book3s_hv_nested.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 41cb03d0bde4..7a0e33a9c980 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -662,8 +662,8 @@ static void kvmppc_end_cede(struct kvm_vcpu *vcpu)
void kvmppc_set_msr_hv(struct kvm_vcpu *vcpu, u64 msr)
{
- /* Guest must always run with ME enabled. */
- msr = msr | MSR_ME;
+ /* Guest must always run with ME enabled, HV disabled. */
+ msr = (msr | MSR_ME) & ~MSR_HV;
/*
* Check for illegal transactional state bit combination
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index fb03085c902b..60724f674421 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -344,8 +344,8 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
vcpu->arch.nested_vcpu_id = l2_hv.vcpu_token;
vcpu->arch.regs = l2_regs;
- /* Guest must always run with ME enabled. */
- vcpu->arch.shregs.msr = vcpu->arch.regs.msr | MSR_ME;
+ /* 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);
--
2.23.0
^ permalink raw reply related
* [PATCH v5 10/48] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: Fabiano Rosas, linuxppc-dev, Nicholas Piggin, Daniel Axtens
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
Rather than add the ME bit to the MSR at guest entry, make it clear
that the hypervisor does not allow the guest to clear the bit.
The ME set is kept in guest entry for now, but a future patch will
warn if it's not present.
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv_builtin.c | 3 +++
arch/powerpc/kvm/book3s_hv_nested.c | 4 +++-
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 158d309b42a3..41cb03d0bde4 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -662,6 +662,9 @@ static void kvmppc_end_cede(struct kvm_vcpu *vcpu)
void kvmppc_set_msr_hv(struct kvm_vcpu *vcpu, u64 msr)
{
+ /* Guest must always run with ME enabled. */
+ msr = msr | MSR_ME;
+
/*
* Check for illegal transactional state bit combination
* and if we find it, force the TS field to a safe state.
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index d14fe32f167b..fb03085c902b 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -343,7 +343,9 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
vcpu->arch.nested = l2;
vcpu->arch.nested_vcpu_id = l2_hv.vcpu_token;
vcpu->arch.regs = l2_regs;
- vcpu->arch.shregs.msr = vcpu->arch.regs.msr;
+
+ /* Guest must always run with ME enabled. */
+ vcpu->arch.shregs.msr = vcpu->arch.regs.msr | MSR_ME;
sanitise_hv_regs(vcpu, &l2_hv);
restore_hv_regs(vcpu, &l2_hv);
--
2.23.0
^ permalink raw reply related
* [PATCH v5 09/48] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: Fabiano Rosas, linuxppc-dev, Nicholas Piggin, Daniel Axtens
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
The code being executed in KVM_GUEST_MODE_SKIP is hypervisor code with
MSR[IR]=0, so the faults of concern are the d-side ones caused by access
to guest context by the hypervisor.
Instruction breakpoint interrupts are not a concern here. It's unlikely
any good would come of causing breaks in this code, but skipping the
instruction that caused it won't help matters (e.g., skip the mtmsr that
sets MSR[DR]=0 or clears KVM_GUEST_MODE_SKIP).
Paul notes: the 0x1300 interrupt was dropped from the architecture a
long time ago and is not generated by P7, P8, P9 or P10.
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index a0515cb829c2..c9c446ccff54 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2553,7 +2553,6 @@ EXC_VIRT_NONE(0x5200, 0x100)
INT_DEFINE_BEGIN(instruction_breakpoint)
IVEC=0x1300
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
- IKVM_SKIP=1
IKVM_REAL=1
#endif
INT_DEFINE_END(instruction_breakpoint)
--
2.23.0
^ permalink raw reply related
* [PATCH v5 08/48] powerpc/64s: Remove KVM handler support from CBE_RAS interrupts
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
Cell does not support KVM.
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 6 ------
1 file changed, 6 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 8082b690e874..a0515cb829c2 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2530,8 +2530,6 @@ EXC_VIRT_NONE(0x5100, 0x100)
INT_DEFINE_BEGIN(cbe_system_error)
IVEC=0x1200
IHSRR=1
- IKVM_SKIP=1
- IKVM_REAL=1
INT_DEFINE_END(cbe_system_error)
EXC_REAL_BEGIN(cbe_system_error, 0x1200, 0x100)
@@ -2701,8 +2699,6 @@ EXC_COMMON_BEGIN(denorm_exception_common)
INT_DEFINE_BEGIN(cbe_maintenance)
IVEC=0x1600
IHSRR=1
- IKVM_SKIP=1
- IKVM_REAL=1
INT_DEFINE_END(cbe_maintenance)
EXC_REAL_BEGIN(cbe_maintenance, 0x1600, 0x100)
@@ -2754,8 +2750,6 @@ EXC_COMMON_BEGIN(altivec_assist_common)
INT_DEFINE_BEGIN(cbe_thermal)
IVEC=0x1800
IHSRR=1
- IKVM_SKIP=1
- IKVM_REAL=1
INT_DEFINE_END(cbe_thermal)
EXC_REAL_BEGIN(cbe_thermal, 0x1800, 0x100)
--
2.23.0
^ permalink raw reply related
* [PATCH v5 07/48] KVM: PPC: Book3S HV: Fix CONFIG_SPAPR_TCE_IOMMU=n default hcalls
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Daniel Axtens
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
This config option causes the warning in init_default_hcalls to fire
because the TCE handlers are in the default hcall list but not
implemented.
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 8bc2a5ee9ece..ed77aff9cdb6 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -5409,8 +5409,10 @@ static unsigned int default_hcall_list[] = {
H_READ,
H_PROTECT,
H_BULK_REMOVE,
+#ifdef CONFIG_SPAPR_TCE_IOMMU
H_GET_TCE,
H_PUT_TCE,
+#endif
H_SET_DABR,
H_SET_XDABR,
H_CEDE,
--
2.23.0
^ permalink raw reply related
* [PATCH v5 06/48] KVM: PPC: Book3S HV: remove unused kvmppc_h_protect argument
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Daniel Axtens
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
The va argument is not used in the function or set by its asm caller,
so remove it to be safe.
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/kvm_ppc.h | 3 +--
arch/powerpc/kvm/book3s_hv_rm_mmu.c | 3 +--
2 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 8aacd76bb702..9531b1c1b190 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -767,8 +767,7 @@ long kvmppc_h_remove(struct kvm_vcpu *vcpu, unsigned long flags,
unsigned long pte_index, unsigned long avpn);
long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu);
long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
- unsigned long pte_index, unsigned long avpn,
- unsigned long va);
+ unsigned long pte_index, unsigned long avpn);
long kvmppc_h_read(struct kvm_vcpu *vcpu, unsigned long flags,
unsigned long pte_index);
long kvmppc_h_clear_ref(struct kvm_vcpu *vcpu, unsigned long flags,
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 88da2764c1bb..7af7c70f1468 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -673,8 +673,7 @@ long kvmppc_h_bulk_remove(struct kvm_vcpu *vcpu)
}
long kvmppc_h_protect(struct kvm_vcpu *vcpu, unsigned long flags,
- unsigned long pte_index, unsigned long avpn,
- unsigned long va)
+ unsigned long pte_index, unsigned long avpn)
{
struct kvm *kvm = vcpu->kvm;
__be64 *hpte;
--
2.23.0
^ permalink raw reply related
* [PATCH v5 05/48] KVM: PPC: Book3S HV: Remove redundant mtspr PSPB
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: Daniel Axtens, linuxppc-dev, Nicholas Piggin, Fabiano Rosas
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
This SPR is set to 0 twice when exiting the guest.
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Suggested-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index a6b5d79d9306..8bc2a5ee9ece 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3787,7 +3787,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
mtspr(SPRN_DSCR, host_dscr);
mtspr(SPRN_TIDR, host_tidr);
mtspr(SPRN_IAMR, host_iamr);
- mtspr(SPRN_PSPB, 0);
if (host_amr != vcpu->arch.amr)
mtspr(SPRN_AMR, host_amr);
--
2.23.0
^ permalink raw reply related
* [PATCH v5 04/48] KVM: PPC: Book3S HV: Prevent radix guests setting LPCR[TC]
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: Alexey Kardashevskiy, linuxppc-dev, Nicholas Piggin
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
Prevent radix guests setting LPCR[TC]. This bit only applies to hash
partitions.
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index daded8949a39..a6b5d79d9306 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1645,6 +1645,10 @@ static int kvm_arch_vcpu_ioctl_set_sregs_hv(struct kvm_vcpu *vcpu,
*/
unsigned long kvmppc_filter_lpcr_hv(struct kvm *kvm, unsigned long lpcr)
{
+ /* LPCR_TC only applies to HPT guests */
+ if (kvm_is_radix(kvm))
+ lpcr &= ~LPCR_TC;
+
/* On POWER8 and above, userspace can modify AIL */
if (!cpu_has_feature(CPU_FTR_ARCH_207S))
lpcr &= ~LPCR_AIL;
--
2.23.0
^ permalink raw reply related
* [PATCH v5 03/48] KVM: PPC: Book3S HV: Disallow LPCR[AIL] to be set to 1 or 2
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
These are already disallowed by H_SET_MODE from the guest, also disallow
these by updating LPCR directly.
AIL modes can affect the host interrupt behaviour while the guest LPCR
value is set, so filter it here too.
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Suggested-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d2c7626cb960..daded8949a39 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -803,7 +803,10 @@ static int kvmppc_h_set_mode(struct kvm_vcpu *vcpu, unsigned long mflags,
vcpu->arch.dawrx1 = value2;
return H_SUCCESS;
case H_SET_MODE_RESOURCE_ADDR_TRANS_MODE:
- /* KVM does not support mflags=2 (AIL=2) */
+ /*
+ * KVM does not support mflags=2 (AIL=2) and AIL=1 is reserved.
+ * Keep this in synch with kvmppc_filter_guest_lpcr_hv.
+ */
if (mflags != 0 && mflags != 3)
return H_UNSUPPORTED_FLAG_START;
return H_TOO_HARD;
@@ -1645,6 +1648,8 @@ unsigned long kvmppc_filter_lpcr_hv(struct kvm *kvm, unsigned long lpcr)
/* On POWER8 and above, userspace can modify AIL */
if (!cpu_has_feature(CPU_FTR_ARCH_207S))
lpcr &= ~LPCR_AIL;
+ if ((lpcr & LPCR_AIL) != LPCR_AIL_3)
+ lpcr &= ~LPCR_AIL; /* LPCR[AIL]=1/2 is disallowed */
/*
* On POWER9, allow userspace to enable large decrementer for the
--
2.23.0
^ permalink raw reply related
* [PATCH v5 02/48] KVM: PPC: Book3S HV: Add a function to filter guest LPCR bits
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
Guest LPCR depends on hardware type, and future changes will add
restrictions based on errata and guest MMU mode. Move this logic
to a common function and use it for the cases where the guest
wants to update its LPCR (or the LPCR of a nested guest).
This also adds a warning in other places that set or update LPCR
if we try to set something that would have been disallowed by
the filter, as a sanity check.
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/kvm_book3s.h | 2 +
arch/powerpc/kvm/book3s_hv.c | 68 ++++++++++++++++++++-------
arch/powerpc/kvm/book3s_hv_nested.c | 8 +++-
3 files changed, 59 insertions(+), 19 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 2f5f919f6cd3..c58121508157 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -258,6 +258,8 @@ extern long kvmppc_hv_get_dirty_log_hpt(struct kvm *kvm,
extern void kvmppc_harvest_vpa_dirty(struct kvmppc_vpa *vpa,
struct kvm_memory_slot *memslot,
unsigned long *map);
+extern unsigned long kvmppc_filter_lpcr_hv(struct kvm *kvm,
+ unsigned long lpcr);
extern void kvmppc_update_lpcr(struct kvm *kvm, unsigned long lpcr,
unsigned long mask);
extern void kvmppc_set_fscr(struct kvm_vcpu *vcpu, u64 fscr);
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 13bad6bf4c95..d2c7626cb960 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1635,6 +1635,35 @@ static int kvm_arch_vcpu_ioctl_set_sregs_hv(struct kvm_vcpu *vcpu,
return 0;
}
+/*
+ * Enforce limits on guest LPCR values based on hardware availability,
+ * guest configuration, and possibly hypervisor support and security
+ * concerns.
+ */
+unsigned long kvmppc_filter_lpcr_hv(struct kvm *kvm, unsigned long lpcr)
+{
+ /* On POWER8 and above, userspace can modify AIL */
+ if (!cpu_has_feature(CPU_FTR_ARCH_207S))
+ lpcr &= ~LPCR_AIL;
+
+ /*
+ * On POWER9, allow userspace to enable large decrementer for the
+ * guest, whether or not the host has it enabled.
+ */
+ if (!cpu_has_feature(CPU_FTR_ARCH_300))
+ lpcr &= ~LPCR_LD;
+
+ return lpcr;
+}
+
+static void verify_lpcr(struct kvm *kvm, unsigned long lpcr)
+{
+ if (lpcr != kvmppc_filter_lpcr_hv(kvm, lpcr)) {
+ WARN_ONCE(1, "lpcr 0x%lx differs from filtered 0x%lx\n",
+ lpcr, kvmppc_filter_lpcr_hv(kvm, lpcr));
+ }
+}
+
static void kvmppc_set_lpcr(struct kvm_vcpu *vcpu, u64 new_lpcr,
bool preserve_top32)
{
@@ -1643,6 +1672,23 @@ static void kvmppc_set_lpcr(struct kvm_vcpu *vcpu, u64 new_lpcr,
u64 mask;
spin_lock(&vc->lock);
+
+ /*
+ * Userspace can only modify
+ * DPFD (default prefetch depth), ILE (interrupt little-endian),
+ * TC (translation control), AIL (alternate interrupt location),
+ * LD (large decrementer).
+ * These are subject to restrictions from kvmppc_filter_lcpr_hv().
+ */
+ mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD;
+
+ /* Broken 32-bit version of LPCR must not clear top bits */
+ if (preserve_top32)
+ mask &= 0xFFFFFFFF;
+
+ new_lpcr = kvmppc_filter_lpcr_hv(kvm,
+ (vc->lpcr & ~mask) | (new_lpcr & mask));
+
/*
* If ILE (interrupt little-endian) has changed, update the
* MSR_LE bit in the intr_msr for each vcpu in this vcore.
@@ -1661,25 +1707,8 @@ static void kvmppc_set_lpcr(struct kvm_vcpu *vcpu, u64 new_lpcr,
}
}
- /*
- * Userspace can only modify DPFD (default prefetch depth),
- * ILE (interrupt little-endian) and TC (translation control).
- * On POWER8 and POWER9 userspace can also modify AIL (alt. interrupt loc.).
- */
- mask = LPCR_DPFD | LPCR_ILE | LPCR_TC;
- if (cpu_has_feature(CPU_FTR_ARCH_207S))
- mask |= LPCR_AIL;
- /*
- * On POWER9, allow userspace to enable large decrementer for the
- * guest, whether or not the host has it enabled.
- */
- if (cpu_has_feature(CPU_FTR_ARCH_300))
- mask |= LPCR_LD;
+ vc->lpcr = new_lpcr;
- /* Broken 32-bit version of LPCR must not clear top bits */
- if (preserve_top32)
- mask &= 0xFFFFFFFF;
- vc->lpcr = (vc->lpcr & ~mask) | (new_lpcr & mask);
spin_unlock(&vc->lock);
}
@@ -4641,8 +4670,10 @@ void kvmppc_update_lpcr(struct kvm *kvm, unsigned long lpcr, unsigned long mask)
struct kvmppc_vcore *vc = kvm->arch.vcores[i];
if (!vc)
continue;
+
spin_lock(&vc->lock);
vc->lpcr = (vc->lpcr & ~mask) | lpcr;
+ verify_lpcr(kvm, vc->lpcr);
spin_unlock(&vc->lock);
if (++cores_done >= kvm->arch.online_vcores)
break;
@@ -4970,6 +5001,7 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
kvmppc_setup_partition_table(kvm);
}
+ verify_lpcr(kvm, lpcr);
kvm->arch.lpcr = lpcr;
/* Initialization for future HPT resizes */
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 3060e5deffc8..d14fe32f167b 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -151,7 +151,13 @@ static void sanitise_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
*/
mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD |
LPCR_LPES | LPCR_MER;
- hr->lpcr = (vc->lpcr & ~mask) | (hr->lpcr & mask);
+
+ /*
+ * 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,
--
2.23.0
^ permalink raw reply related
* [PATCH v5 01/48] KVM: PPC: Book3S HV: Nested move LPCR sanitising to sanitise_hv_regs
From: Nicholas Piggin @ 2021-04-01 15:02 UTC (permalink / raw)
To: kvm-ppc; +Cc: linuxppc-dev, Nicholas Piggin, Fabiano Rosas
In-Reply-To: <20210401150325.442125-1-npiggin@gmail.com>
This will get a bit more complicated in future patches. Move it
into the helper function.
This change allows the L1 hypervisor to determine some of the LPCR
bits that the L0 is using to run it, which could be a privilege
violation (LPCR is HV-privileged), although the same problem exists
now for HFSCR for example. Discussion of the HV privilege issue is
ongoing and can be resolved with a later change.
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv_nested.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 0cd0e7aad588..3060e5deffc8 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -132,8 +132,27 @@ static void save_hv_return_state(struct kvm_vcpu *vcpu, int trap,
}
}
+/*
+ * 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;
+ hr->lpcr = (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.
@@ -271,8 +290,6 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
u64 hv_ptr, regs_ptr;
u64 hdec_exp;
s64 delta_purr, delta_spurr, delta_ic, delta_vtb;
- u64 mask;
- unsigned long lpcr;
if (vcpu->kvm->arch.l1_ptcr == 0)
return H_NOT_AVAILABLE;
@@ -321,9 +338,7 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
vcpu->arch.nested_vcpu_id = l2_hv.vcpu_token;
vcpu->arch.regs = l2_regs;
vcpu->arch.shregs.msr = vcpu->arch.regs.msr;
- mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD |
- LPCR_LPES | LPCR_MER;
- lpcr = (vc->lpcr & ~mask) | (l2_hv.lpcr & mask);
+
sanitise_hv_regs(vcpu, &l2_hv);
restore_hv_regs(vcpu, &l2_hv);
@@ -335,7 +350,7 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
r = RESUME_HOST;
break;
}
- r = kvmhv_run_single_vcpu(vcpu, hdec_exp, lpcr);
+ r = kvmhv_run_single_vcpu(vcpu, hdec_exp, l2_hv.lpcr);
} while (is_kvmppc_resume_guest(r));
/* save L2 state for return */
--
2.23.0
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