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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] xen/arm: Implement PSCI SYSTEM_SUSPEND call for guests
commit 1e3dc2f86695687e354d14091aa876149de4fcdc
Author: Mykola Kvach <mykola_kvach@xxxxxxxx>
AuthorDate: Tue Mar 24 14:26:34 2026 +0200
Commit: Michal Orzel <michal.orzel@xxxxxxx>
CommitDate: Tue Mar 31 10:54:46 2026 +0200
xen/arm: Implement PSCI SYSTEM_SUSPEND call for guests
Add support for the PSCI SYSTEM_SUSPEND function in the vPSCI interface,
allowing guests to request suspend via the PSCI v1.0+ SYSTEM_SUSPEND call
(both 32-bit and 64-bit variants).
Implementation details:
- Add SYSTEM_SUSPEND function IDs to PSCI definitions
- Trap and handle SYSTEM_SUSPEND in vPSCI
- Reject SYSTEM_SUSPEND for the hardware domain to avoid host shutdown
- Require all secondary VCPUs to be offline before suspend
- Split arch_set_info_guest() into arch_vcpu_validate_guest_context() and
arch_vcpu_apply_guest_context() for reuse by vPSCI
- Add vpsci_build_guest_context() helper and store prevalidated context in
resume_ctx; resume applies it and frees it
- Add arch_domain_resume() function is an architecture-specific hook that
is invoked during domain resume to perform any necessary setup or
restoration steps required by the platform.
Usage:
For Linux-based guests, suspend can be initiated with:
echo mem > /sys/power/state
or via:
systemctl suspend
Resume from control domain:
xl resume <domain>
Signed-off-by: Mykola Kvach <mykola_kvach@xxxxxxxx>
Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
---
xen/arch/arm/domain.c | 86 ++++++++++++++++----
xen/arch/arm/include/asm/domain.h | 7 ++
xen/arch/arm/include/asm/perfc_defn.h | 1 +
xen/arch/arm/include/asm/psci.h | 2 +
xen/arch/arm/include/asm/suspend.h | 27 +++++++
xen/arch/arm/include/asm/vpsci.h | 2 +-
xen/arch/arm/vpsci.c | 146 +++++++++++++++++++++++++++-------
xen/common/domain.c | 4 +
xen/include/xen/suspend.h | 22 +++++
9 files changed, 255 insertions(+), 42 deletions(-)
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 94b9858ad2..581f82bddd 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -12,6 +12,8 @@
#include <xen/softirq.h>
#include <xen/wait.h>
+#include <public/sched.h>
+
#include <asm/arm64/sve.h>
#include <asm/cpuerrata.h>
#include <asm/cpufeature.h>
@@ -24,10 +26,12 @@
#include <asm/platform.h>
#include <asm/procinfo.h>
#include <asm/regs.h>
+#include <asm/suspend.h>
#include <asm/firmware/sci.h>
#include <asm/tee/tee.h>
#include <asm/vfp.h>
#include <asm/vgic.h>
+#include <asm/vpsci.h>
#include <asm/vtimer.h>
#include "vpci.h"
@@ -770,8 +774,18 @@ int arch_domain_teardown(struct domain *d)
return 0;
}
+static void resume_ctx_reset(struct resume_info *ctx)
+{
+ if ( ctx->ctxt )
+ free_vcpu_guest_context(ctx->ctxt);
+
+ memset(ctx, 0, sizeof(*ctx));
+}
+
void arch_domain_destroy(struct domain *d)
{
+ resume_ctx_reset(&d->arch.resume_ctx);
+
tee_free_domain_ctx(d);
/* IOMMU page table is shared with P2M, always call
* iommu_domain_destroy() before p2m_final_teardown().
@@ -806,6 +820,28 @@ void arch_domain_creation_finished(struct domain *d)
p2m_domain_creation_finished(d);
}
+void arch_domain_resume(struct domain *d)
+{
+ struct resume_info *ctx = &d->arch.resume_ctx;
+
+ /*
+ * It is still possible to call domain_shutdown() with a suspend reason
+ * via some hypercalls, such as SCHEDOP_shutdown or
SCHEDOP_remote_shutdown.
+ * In these cases, the resume context will be empty, so there is no
+ * suspend-specific state to restore.
+ */
+ if ( !ctx->wake_cpu )
+ return;
+
+ ASSERT(d->shutdown_code == SHUTDOWN_suspend);
+
+ domain_lock(d);
+ arch_vcpu_apply_guest_context(ctx->wake_cpu, ctx->ctxt);
+ domain_unlock(d);
+
+ resume_ctx_reset(ctx);
+}
+
static int is_guest_pv32_psr(uint32_t psr)
{
switch (psr & PSR_MODE_MASK)
@@ -848,15 +884,32 @@ static int is_guest_pv64_psr(uint64_t psr)
}
#endif
+void arch_vcpu_apply_guest_context(struct vcpu *v,
+ const struct vcpu_guest_context *ctxt)
+{
+ vcpu_regs_user_to_hyp(v, &ctxt->user_regs);
+
+ v->arch.sctlr = ctxt->sctlr;
+ v->arch.ttbr0 = ctxt->ttbr0;
+ v->arch.ttbr1 = ctxt->ttbr1;
+ v->arch.ttbcr = ctxt->ttbcr;
+
+ v->is_initialised = 1;
+
+ if ( ctxt->flags & VGCF_online )
+ clear_bit(_VPF_down, &v->pause_flags);
+ else
+ set_bit(_VPF_down, &v->pause_flags);
+}
+
/*
* Initialise vCPU state. The context may be supplied by an external entity, so
* we need to validate it.
*/
-int arch_set_info_guest(
- struct vcpu *v, vcpu_guest_context_u c)
+int arch_vcpu_validate_guest_context(const struct vcpu *v,
+ const struct vcpu_guest_context *ctxt)
{
- struct vcpu_guest_context *ctxt = c.nat;
- struct vcpu_guest_core_regs *regs = &c.nat->user_regs;
+ const struct vcpu_guest_core_regs *regs = &ctxt->user_regs;
if ( is_32bit_domain(v->domain) )
{
@@ -885,19 +938,24 @@ int arch_set_info_guest(
}
#endif
- vcpu_regs_user_to_hyp(v, regs);
+ return 0;
+}
- v->arch.sctlr = ctxt->sctlr;
- v->arch.ttbr0 = ctxt->ttbr0;
- v->arch.ttbr1 = ctxt->ttbr1;
- v->arch.ttbcr = ctxt->ttbcr;
+/*
+ * Initialise vCPU state. The context may be supplied by an external entity, so
+ * we need to validate it.
+ */
+int arch_set_info_guest(
+ struct vcpu *v, vcpu_guest_context_u c)
+{
+ struct vcpu_guest_context *ctxt = c.nat;
+ int rc;
- v->is_initialised = 1;
+ rc = arch_vcpu_validate_guest_context(v, ctxt);
+ if ( rc )
+ return rc;
- if ( ctxt->flags & VGCF_online )
- clear_bit(_VPF_down, &v->pause_flags);
- else
- set_bit(_VPF_down, &v->pause_flags);
+ arch_vcpu_apply_guest_context(v, ctxt);
return 0;
}
diff --git a/xen/arch/arm/include/asm/domain.h
b/xen/arch/arm/include/asm/domain.h
index 758ad807e4..ffe5d0d9f0 100644
--- a/xen/arch/arm/include/asm/domain.h
+++ b/xen/arch/arm/include/asm/domain.h
@@ -5,6 +5,7 @@
#include <xen/timer.h>
#include <asm/page.h>
#include <asm/p2m.h>
+#include <asm/suspend.h>
#include <asm/vfp.h>
#include <asm/mmio.h>
#include <asm/gic.h>
@@ -126,6 +127,7 @@ struct arch_domain
void *sci_data;
#endif
+ struct resume_info resume_ctx;
} __cacheline_aligned;
struct arch_vcpu
@@ -290,6 +292,11 @@ static inline register_t vcpuid_to_vaffinity(unsigned int
vcpuid)
return vaff;
}
+int arch_vcpu_validate_guest_context(const struct vcpu *v,
+ const struct vcpu_guest_context *ctxt);
+void arch_vcpu_apply_guest_context(struct vcpu *v,
+ const struct vcpu_guest_context *ctxt);
+
static inline struct vcpu_guest_context *alloc_vcpu_guest_context(void)
{
return xmalloc(struct vcpu_guest_context);
diff --git a/xen/arch/arm/include/asm/perfc_defn.h
b/xen/arch/arm/include/asm/perfc_defn.h
index effd25b69e..8dfcac7e3b 100644
--- a/xen/arch/arm/include/asm/perfc_defn.h
+++ b/xen/arch/arm/include/asm/perfc_defn.h
@@ -33,6 +33,7 @@ PERFCOUNTER(vpsci_system_reset, "vpsci: system_reset")
PERFCOUNTER(vpsci_cpu_suspend, "vpsci: cpu_suspend")
PERFCOUNTER(vpsci_cpu_affinity_info, "vpsci: cpu_affinity_info")
PERFCOUNTER(vpsci_features, "vpsci: features")
+PERFCOUNTER(vpsci_system_suspend, "vpsci: system_suspend")
PERFCOUNTER(vcpu_kick, "vcpu: notify other vcpu")
diff --git a/xen/arch/arm/include/asm/psci.h b/xen/arch/arm/include/asm/psci.h
index 4780972621..48a93e6b79 100644
--- a/xen/arch/arm/include/asm/psci.h
+++ b/xen/arch/arm/include/asm/psci.h
@@ -47,10 +47,12 @@ void call_psci_system_reset(void);
#define PSCI_0_2_FN32_SYSTEM_OFF PSCI_0_2_FN32(8)
#define PSCI_0_2_FN32_SYSTEM_RESET PSCI_0_2_FN32(9)
#define PSCI_1_0_FN32_PSCI_FEATURES PSCI_0_2_FN32(10)
+#define PSCI_1_0_FN32_SYSTEM_SUSPEND PSCI_0_2_FN32(14)
#define PSCI_0_2_FN64_CPU_SUSPEND PSCI_0_2_FN64(1)
#define PSCI_0_2_FN64_CPU_ON PSCI_0_2_FN64(3)
#define PSCI_0_2_FN64_AFFINITY_INFO PSCI_0_2_FN64(4)
+#define PSCI_1_0_FN64_SYSTEM_SUSPEND PSCI_0_2_FN64(14)
/* PSCI v0.2 affinity level state returned by AFFINITY_INFO */
#define PSCI_0_2_AFFINITY_LEVEL_ON 0
diff --git a/xen/arch/arm/include/asm/suspend.h
b/xen/arch/arm/include/asm/suspend.h
new file mode 100644
index 0000000000..31a98a1f1b
--- /dev/null
+++ b/xen/arch/arm/include/asm/suspend.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef ARM_SUSPEND_H
+#define ARM_SUSPEND_H
+
+struct domain;
+struct vcpu;
+struct vcpu_guest_context;
+
+struct resume_info {
+ struct vcpu_guest_context *ctxt;
+ struct vcpu *wake_cpu;
+};
+
+void arch_domain_resume(struct domain *d);
+
+#endif /* ARM_SUSPEND_H */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/arm/include/asm/vpsci.h b/xen/arch/arm/include/asm/vpsci.h
index 0cca5e6830..69d40f9d7f 100644
--- a/xen/arch/arm/include/asm/vpsci.h
+++ b/xen/arch/arm/include/asm/vpsci.h
@@ -23,7 +23,7 @@
#include <asm/psci.h>
/* Number of function implemented by virtual PSCI (only 0.2 or later) */
-#define VPSCI_NR_FUNCS 12
+#define VPSCI_NR_FUNCS 14
/* Functions handle PSCI calls from the guests */
bool do_vpsci_0_1_call(struct cpu_user_regs *regs, uint32_t fid);
diff --git a/xen/arch/arm/vpsci.c b/xen/arch/arm/vpsci.c
index 7ba9ccd94b..bd87ec430d 100644
--- a/xen/arch/arm/vpsci.c
+++ b/xen/arch/arm/vpsci.c
@@ -4,38 +4,24 @@
#include <xen/types.h>
#include <asm/current.h>
+#include <asm/domain.h>
#include <asm/vgic.h>
#include <asm/vpsci.h>
#include <asm/event.h>
#include <public/sched.h>
-static int do_common_cpu_on(register_t target_cpu, register_t entry_point,
- register_t context_id)
+static int vpsci_build_guest_context(struct vcpu *v, register_t entry_point,
+ register_t context_id,
+ struct vcpu_guest_context **out)
{
- struct vcpu *v;
- struct domain *d = current->domain;
+ bool is_thumb = entry_point & 1;
struct vcpu_guest_context *ctxt;
int rc;
- bool is_thumb = entry_point & 1;
- register_t vcpuid;
-
- vcpuid = vaffinity_to_vcpuid(target_cpu);
- if ( (v = domain_vcpu(d, vcpuid)) == NULL )
- return PSCI_INVALID_PARAMETERS;
-
- /* THUMB set is not allowed with 64-bit domain */
- if ( is_64bit_domain(d) && is_thumb )
- return PSCI_INVALID_ADDRESS;
-
- if ( !test_bit(_VPF_down, &v->pause_flags) )
- return PSCI_ALREADY_ON;
-
- if ( (ctxt = alloc_vcpu_guest_context()) == NULL )
- return PSCI_DENIED;
-
- vgic_clear_pending_irqs(v);
+ ctxt = alloc_vcpu_guest_context();
+ if ( ctxt == NULL )
+ return -ENOMEM;
memset(ctxt, 0, sizeof(*ctxt));
ctxt->user_regs.pc64 = (u64) entry_point;
@@ -48,7 +34,7 @@ static int do_common_cpu_on(register_t target_cpu, register_t
entry_point,
* x0/r0_usr are always updated because for PSCI 0.1 the general
* purpose registers are undefined upon CPU_on.
*/
- if ( is_32bit_domain(d) )
+ if ( is_32bit_domain(v->domain) )
{
ctxt->user_regs.cpsr = PSR_GUEST32_INIT;
/* Start the VCPU with THUMB set if it's requested by the kernel */
@@ -69,15 +55,51 @@ static int do_common_cpu_on(register_t target_cpu,
register_t entry_point,
#endif
ctxt->flags = VGCF_online;
- domain_lock(d);
- rc = arch_set_info_guest(v, ctxt);
- domain_unlock(d);
+ rc = arch_vcpu_validate_guest_context(v, ctxt);
+ if ( rc )
+ {
+ free_vcpu_guest_context(ctxt);
+ return rc;
+ }
- free_vcpu_guest_context(ctxt);
+ *out = ctxt;
+ return 0;
+}
+
+static int do_common_cpu_on(register_t target_cpu, register_t entry_point,
+ register_t context_id)
+{
+ struct vcpu *v;
+ struct domain *d = current->domain;
+ struct vcpu_guest_context *ctxt = NULL;
+ int rc;
+ bool is_thumb = entry_point & 1;
+ register_t vcpuid;
+
+ vcpuid = vaffinity_to_vcpuid(target_cpu);
+
+ if ( (v = domain_vcpu(d, vcpuid)) == NULL )
+ return PSCI_INVALID_PARAMETERS;
+
+ /* THUMB set is not allowed with 64-bit domain */
+ if ( is_64bit_domain(d) && is_thumb )
+ return PSCI_INVALID_ADDRESS;
+ if ( !test_bit(_VPF_down, &v->pause_flags) )
+ return PSCI_ALREADY_ON;
+
+ rc = vpsci_build_guest_context(v, entry_point, context_id, &ctxt);
if ( rc < 0 )
return PSCI_DENIED;
+ vgic_clear_pending_irqs(v);
+
+ domain_lock(d);
+ arch_vcpu_apply_guest_context(v, ctxt);
+ domain_unlock(d);
+
+ free_vcpu_guest_context(ctxt);
+
vcpu_wake(v);
return PSCI_SUCCESS;
@@ -197,6 +219,56 @@ static void do_psci_0_2_system_reset(void)
domain_shutdown(d,SHUTDOWN_reboot);
}
+static int32_t do_psci_1_0_system_suspend(register_t epoint, register_t cid)
+{
+ int32_t rc;
+ struct vcpu_guest_context *ctxt;
+ struct vcpu *v;
+ struct domain *d = current->domain;
+ bool is_thumb = epoint & 1;
+ struct resume_info *rctx = &d->arch.resume_ctx;
+
+ /* THUMB set is not allowed with 64-bit domain */
+ if ( is_64bit_domain(d) && is_thumb )
+ return PSCI_INVALID_ADDRESS;
+
+ /* SYSTEM_SUSPEND is not supported for the hardware domain yet */
+ if ( is_hardware_domain(d) )
+ return PSCI_NOT_SUPPORTED;
+
+ /* Ensure that all CPUs other than the calling one are offline */
+ domain_lock(d);
+ for_each_vcpu ( d, v )
+ {
+ if ( v != current && is_vcpu_online(v) )
+ {
+ domain_unlock(d);
+ return PSCI_DENIED;
+ }
+ }
+ domain_unlock(d);
+
+ rc = vpsci_build_guest_context(current, epoint, cid, &ctxt);
+ if ( rc )
+ return PSCI_DENIED;
+
+ rc = domain_shutdown(d, SHUTDOWN_suspend);
+ if ( rc )
+ {
+ free_vcpu_guest_context(ctxt);
+ return PSCI_DENIED;
+ }
+
+ rctx->ctxt = ctxt;
+ rctx->wake_cpu = current;
+
+ gprintk(XENLOG_DEBUG,
+ "SYSTEM_SUSPEND requested, epoint=%#"PRIregister",
cid=%#"PRIregister"\n",
+ epoint, cid);
+
+ return rc;
+}
+
static int32_t do_psci_1_0_features(uint32_t psci_func_id)
{
/* /!\ Ordered by function ID and not name */
@@ -216,6 +288,9 @@ static int32_t do_psci_1_0_features(uint32_t psci_func_id)
case PSCI_1_0_FN32_PSCI_FEATURES:
case ARM_SMCCC_VERSION_FID:
return 0;
+ case PSCI_1_0_FN32_SYSTEM_SUSPEND:
+ case PSCI_1_0_FN64_SYSTEM_SUSPEND:
+ return is_hardware_domain(current->domain) ? PSCI_NOT_SUPPORTED : 0;
default:
return PSCI_NOT_SUPPORTED;
}
@@ -344,6 +419,23 @@ bool do_vpsci_0_2_call(struct cpu_user_regs *regs,
uint32_t fid)
return true;
}
+ case PSCI_1_0_FN32_SYSTEM_SUSPEND:
+ case PSCI_1_0_FN64_SYSTEM_SUSPEND:
+ {
+ register_t epoint = PSCI_ARG(regs, 1);
+ register_t cid = PSCI_ARG(regs, 2);
+
+ if ( fid == PSCI_1_0_FN32_SYSTEM_SUSPEND )
+ {
+ epoint &= GENMASK(31, 0);
+ cid &= GENMASK(31, 0);
+ }
+
+ perfc_incr(vpsci_system_suspend);
+ PSCI_SET_RESULT(regs, do_psci_1_0_system_suspend(epoint, cid));
+ return true;
+ }
+
default:
return false;
}
diff --git a/xen/common/domain.c b/xen/common/domain.c
index 30cfea3045..bb9e210c28 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -26,6 +26,7 @@
#include <xen/hypercall.h>
#include <xen/delay.h>
#include <xen/shutdown.h>
+#include <xen/suspend.h>
#include <xen/percpu.h>
#include <xen/multicall.h>
#include <xen/rcupdate.h>
@@ -1435,6 +1436,9 @@ void domain_resume(struct domain *d)
spin_lock(&d->shutdown_lock);
d->is_shutting_down = d->is_shut_down = 0;
+
+ arch_domain_resume(d);
+
d->shutdown_code = SHUTDOWN_CODE_INVALID;
for_each_vcpu ( d, v )
diff --git a/xen/include/xen/suspend.h b/xen/include/xen/suspend.h
new file mode 100644
index 0000000000..6f94fd53b0
--- /dev/null
+++ b/xen/include/xen/suspend.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef XEN_SUSPEND_H
+#define XEN_SUSPEND_H
+
+#if __has_include(<asm/suspend.h>)
+#include <asm/suspend.h>
+#else
+static inline void arch_domain_resume(struct domain *d) {}
+#endif
+
+#endif /* XEN_SUSPEND_H */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
--
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