This adds code to handle two new guest-accessible special-purpose
registers on POWER9: TIDR (thread ID register) and PSSCR (processor
stop status and control register). They are context-switched
between host and guest, and the guest values can be read and set
via the one_reg interface.
The PSSCR contains some fields which are guest-accessible and some
which are only accessible in hypervisor mode. We only allow the
guest-accessible fields to be read or set by userspace.
Signed-off-by: Paul Mackerras <pau...@ozlabs.org>
---
Documentation/virtual/kvm/api.txt | 2 ++
arch/powerpc/include/asm/kvm_host.h | 2 ++
arch/powerpc/include/uapi/asm/kvm.h | 4 ++++
arch/powerpc/kernel/asm-offsets.c | 2 ++
arch/powerpc/kvm/book3s_hv.c | 12 ++++++++++
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 39 +++++++++++++++++++++++++++++++--
6 files changed, 59 insertions(+), 2 deletions(-)
diff --git a/Documentation/virtual/kvm/api.txt
b/Documentation/virtual/kvm/api.txt
index 739db9a..40b2bfc 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2023,6 +2023,8 @@ registers, find a list below:
PPC | KVM_REG_PPC_WORT | 64
PPC | KVM_REG_PPC_SPRG9 | 64
PPC | KVM_REG_PPC_DBSR | 32
+ PPC | KVM_REG_PPC_TIDR | 64
+ PPC | KVM_REG_PPC_PSSCR | 64
PPC | KVM_REG_PPC_TM_GPR0 | 64
...
PPC | KVM_REG_PPC_TM_GPR31 | 64
diff --git a/arch/powerpc/include/asm/kvm_host.h
b/arch/powerpc/include/asm/kvm_host.h
index 20ef27d..0d94608 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -517,6 +517,8 @@ struct kvm_vcpu_arch {
ulong tcscr;
ulong acop;
ulong wort;
+ ulong tid;
+ ulong psscr;
ulong shadow_srr1;
#endif
u32 vrsave; /* also USPRG0 */
diff --git a/arch/powerpc/include/uapi/asm/kvm.h
b/arch/powerpc/include/uapi/asm/kvm.h
index c93cf35..f0bae66 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -573,6 +573,10 @@ struct kvm_get_htab_header {
#define KVM_REG_PPC_SPRG9 (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xba)
#define KVM_REG_PPC_DBSR (KVM_REG_PPC | KVM_REG_SIZE_U32 | 0xbb)
+/* POWER9 registers */
+#define KVM_REG_PPC_TIDR (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xbc)
+#define KVM_REG_PPC_PSSCR (KVM_REG_PPC | KVM_REG_SIZE_U64 | 0xbd)
+
/* Transactional Memory checkpointed state:
* This is all GPRs, all VSX regs and a subset of SPRs
*/
diff --git a/arch/powerpc/kernel/asm-offsets.c
b/arch/powerpc/kernel/asm-offsets.c
index caec7bf..494241b 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -548,6 +548,8 @@ int main(void)
DEFINE(VCPU_TCSCR, offsetof(struct kvm_vcpu, arch.tcscr));
DEFINE(VCPU_ACOP, offsetof(struct kvm_vcpu, arch.acop));
DEFINE(VCPU_WORT, offsetof(struct kvm_vcpu, arch.wort));
+ DEFINE(VCPU_TID, offsetof(struct kvm_vcpu, arch.tid));
+ DEFINE(VCPU_PSSCR, offsetof(struct kvm_vcpu, arch.psscr));
DEFINE(VCORE_ENTRY_EXIT, offsetof(struct kvmppc_vcore, entry_exit_map));
DEFINE(VCORE_IN_GUEST, offsetof(struct kvmppc_vcore, in_guest));
DEFINE(VCORE_NAPPING_THREADS, offsetof(struct kvmppc_vcore,
napping_threads));
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 5cbe3c3..59e18dfb 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1230,6 +1230,12 @@ static int kvmppc_get_one_reg_hv(struct kvm_vcpu *vcpu,
u64 id,
case KVM_REG_PPC_WORT:
*val = get_reg_val(id, vcpu->arch.wort);
break;
+ case KVM_REG_PPC_TIDR:
+ *val = get_reg_val(id, vcpu->arch.tid);
+ break;
+ case KVM_REG_PPC_PSSCR:
+ *val = get_reg_val(id, vcpu->arch.psscr);
+ break;
case KVM_REG_PPC_VPA_ADDR:
spin_lock(&vcpu->arch.vpa_update_lock);
*val = get_reg_val(id, vcpu->arch.vpa.next_gpa);
@@ -1428,6 +1434,12 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu,
u64 id,
case KVM_REG_PPC_WORT:
vcpu->arch.wort = set_reg_val(id, *val);
break;
+ case KVM_REG_PPC_TIDR:
+ vcpu->arch.tid = set_reg_val(id, *val);
+ break;
+ case KVM_REG_PPC_PSSCR:
+ vcpu->arch.psscr = set_reg_val(id, *val) & PSSCR_GUEST_VIS;
+ break;
case KVM_REG_PPC_VPA_ADDR:
addr = set_reg_val(id, *val);
r = -EINVAL;
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index d422014..219a04f 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -523,6 +523,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
* *
*****************************************************************************/
+/* Stack frame offsets */
+#define STACK_SLOT_TID (112-16)
+#define STACK_SLOT_PSSCR (112-24)
+
.global kvmppc_hv_entry
kvmppc_hv_entry:
@@ -700,6 +704,14 @@ kvmppc_got_guest:
mtspr SPRN_PURR,r7
mtspr SPRN_SPURR,r8
+ /* Save host values of some registers */
+BEGIN_FTR_SECTION
+ mfspr r5, SPRN_TIDR
+ mfspr r6, SPRN_PSSCR
+ std r5, STACK_SLOT_TID(r1)
+ std r6, STACK_SLOT_PSSCR(r1)
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
+
BEGIN_FTR_SECTION
/* Set partition DABR */
/* Do this before re-enabling PMU to avoid P7 DABR corruption bug */
@@ -824,6 +836,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S)
mtspr SPRN_PID, r7
mtspr SPRN_WORT, r8
BEGIN_FTR_SECTION
+ /* POWER8-only registers */
ld r5, VCPU_TCSCR(r4)
ld r6, VCPU_ACOP(r4)
ld r7, VCPU_CSIGR(r4)
@@ -832,7 +845,14 @@ BEGIN_FTR_SECTION
mtspr SPRN_ACOP, r6
mtspr SPRN_CSIGR, r7
mtspr SPRN_TACR, r8
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
+FTR_SECTION_ELSE
+ /* POWER9-only registers */
+ ld r5, VCPU_TID(r4)
+ ld r6, VCPU_PSSCR(r4)
+ oris r6, r6, PSSCR_EC@h /* This makes stop trap to HV */
+ mtspr SPRN_TIDR, r5
+ mtspr SPRN_PSSCR, r6
+ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
8:
/*
@@ -1362,7 +1382,14 @@ BEGIN_FTR_SECTION
std r6, VCPU_ACOP(r9)
std r7, VCPU_CSIGR(r9)
std r8, VCPU_TACR(r9)
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
+FTR_SECTION_ELSE
+ mfspr r5, SPRN_TIDR
+ mfspr r6, SPRN_PSSCR
+ std r5, VCPU_TID(r9)
+ rldicl r6, r6, 4, 50 /* r6 &= PSSCR_GUEST_VIS */
+ rotldi r6, r6, 60
+ std r6, VCPU_PSSCR(r9)
+ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
/*
* Restore various registers to 0, where non-zero values
* set by the guest could disrupt the host.
@@ -1531,6 +1558,14 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
slbia
ptesync
+ /* Restore host values of some registers */
+BEGIN_FTR_SECTION
+ ld r5, STACK_SLOT_TID(r1)
+ ld r6, STACK_SLOT_PSSCR(r1)
+ mtspr SPRN_TIDR, r5
+ mtspr SPRN_PSSCR, r6
+END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
+
/*
* POWER7/POWER8 guest -> host partition switch code.
* We don't have to lock against tlbies but we do
--
2.7.4
