From 2013c5665cf001f4929e791c9f2262fdb508cf60 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 20 Jan 2017 11:15:10 +0000 Subject: [PATCH] hw/arm/virt: Support using SMC for PSCI If we are giving the guest a CPU with EL2, it is likely to want to use the HVC instruction itself, for instance for providing PSCI to inner guest VMs. This makes using HVC as the PSCI conduit for the outer QEMU a bad idea. We will want to use SMC instead is this case: this makes sense because QEMU's PSCI implementation is effectively an emulation of functionality provided by EL3 firmware. Add code to support selecting the PSCI conduit to use, rather than hardcoding use of HVC. Signed-off-by: Peter Maydell Reviewed-by: Edgar E. Iglesias Reviewed-by: Andrew Jones Message-id: 1483977924-14522-15-git-send-email-peter.maydell@linaro.org --- hw/arm/virt.c | 27 +++++++++++++++++++++------ include/hw/arm/virt.h | 2 +- 2 files changed, 22 insertions(+), 7 deletions(-) diff --git a/hw/arm/virt.c b/hw/arm/virt.c index d931d17fc3..3a6f895686 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -229,9 +229,19 @@ static void fdt_add_psci_node(const VirtMachineState *vms) uint32_t migrate_fn; void *fdt = vms->fdt; ARMCPU *armcpu = ARM_CPU(qemu_get_cpu(0)); + const char *psci_method; - if (!vms->using_psci) { + switch (vms->psci_conduit) { + case QEMU_PSCI_CONDUIT_DISABLED: return; + case QEMU_PSCI_CONDUIT_HVC: + psci_method = "hvc"; + break; + case QEMU_PSCI_CONDUIT_SMC: + psci_method = "smc"; + break; + default: + g_assert_not_reached(); } qemu_fdt_add_subnode(fdt, "/psci"); @@ -263,7 +273,7 @@ static void fdt_add_psci_node(const VirtMachineState *vms) * However, the device tree binding uses 'method' instead, so that is * what we should use here. */ - qemu_fdt_setprop_string(fdt, "/psci", "method", "hvc"); + qemu_fdt_setprop_string(fdt, "/psci", "method", psci_method); qemu_fdt_setprop_cell(fdt, "/psci", "cpu_suspend", cpu_suspend_fn); qemu_fdt_setprop_cell(fdt, "/psci", "cpu_off", cpu_off_fn); @@ -365,7 +375,8 @@ static void fdt_add_cpu_nodes(const VirtMachineState *vms) qemu_fdt_setprop_string(vms->fdt, nodename, "compatible", armcpu->dtb_compatible); - if (vms->using_psci && vms->smp_cpus > 1) { + if (vms->psci_conduit != QEMU_PSCI_CONDUIT_DISABLED + && vms->smp_cpus > 1) { qemu_fdt_setprop_string(vms->fdt, nodename, "enable-method", "psci"); } @@ -1230,7 +1241,11 @@ static void machvirt_init(MachineState *machine) * let the boot ROM sort them out. * The usual case is that we do use QEMU's PSCI implementation. */ - vms->using_psci = !(vms->secure && firmware_loaded); + if (vms->secure && firmware_loaded) { + vms->psci_conduit = QEMU_PSCI_CONDUIT_DISABLED; + } else { + vms->psci_conduit = QEMU_PSCI_CONDUIT_HVC; + } /* The maximum number of CPUs depends on the GIC version, or on how * many redistributors we can fit into the memory map. @@ -1313,8 +1328,8 @@ static void machvirt_init(MachineState *machine) object_property_set_bool(cpuobj, false, "has_el3", NULL); } - if (vms->using_psci) { - object_property_set_int(cpuobj, QEMU_PSCI_CONDUIT_HVC, + if (vms->psci_conduit != QEMU_PSCI_CONDUIT_DISABLED) { + object_property_set_int(cpuobj, vms->psci_conduit, "psci-conduit", NULL); /* Secondary CPUs start in PSCI powered-down state */ diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h index b8a19ec002..53507e63d0 100644 --- a/include/hw/arm/virt.h +++ b/include/hw/arm/virt.h @@ -103,7 +103,7 @@ typedef struct { uint32_t clock_phandle; uint32_t gic_phandle; uint32_t msi_phandle; - bool using_psci; + int psci_conduit; } VirtMachineState; #define TYPE_VIRT_MACHINE MACHINE_TYPE_NAME("virt")