[PATCH 13/13] KVM: PPC: Book3S HV: Implement the rest of the P9 entry/exit handling in C
Nicholas Piggin
npiggin at gmail.com
Fri Feb 19 17:35:42 AEDT 2021
Almost all logic is moved to C, by introducing a new in_guest mode that
selects and branches very early in the interrupt handler to the P9 exit
code.
The remaining assembly is only about 160 lines of low level stack setup,
with VCPU vs host register save and restore, plus a small shim to the
legacy paths in the interrupt handler.
There are two motivations for this, the first is just make the code more
maintainable being in C. The second is to reduce the amount of code
running in a special KVM mode, "realmode". I put that in quotes because
with radix it is no longer necessarily real-mode in the MMU, but it
still has to be treated specially because it may be in real-mode, and
has various important registers like PID, DEC, TB, etc set to guest.
This is hostile to the rest of Linux and can't use arbitrary kernel
functionality or be instrumented well.
This initial patch is a reasonably faithful conversion of the asm code,
one notable difference being no real-mode hcall handler which necessitates
a small change to the H_CEDE call (although that makes it nicely common
with the nested HV case).
This also lacks any loop to return quickly back into the guest without
switching out of realmode in the case of unimportant or easily handled
interrupts.
The point was to reduce complexity and improve the ability to instrument
things, and it actually remains to be seen whether these short cuts are
required for modern processors. Radix, independent threads, XIVE, large
decrementer etc should all combine to vastly reduce guest exit frequency
compared with a POWER8. And radix mode additionally makes such exits
less costly by avoiding the need to flush and reload the SLB, flush
ERATs, etc.
Some of these things may be re-added if performance requires, or if more
of the other paths begin to be converted into C as well.
not-yet-Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
arch/powerpc/include/asm/asm-prototypes.h | 3 +-
arch/powerpc/include/asm/kvm_asm.h | 3 +-
arch/powerpc/include/asm/kvm_book3s_64.h | 2 +
arch/powerpc/include/asm/kvm_ppc.h | 2 +
arch/powerpc/kernel/security.c | 5 +-
arch/powerpc/kvm/Makefile | 3 +
arch/powerpc/kvm/book3s_64_entry.S | 180 +++++++++++++++++++
arch/powerpc/kvm/book3s_hv.c | 19 +-
arch/powerpc/kvm/book3s_hv_interrupt.c | 208 ++++++++++++++++++++++
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 112 +-----------
arch/powerpc/kvm/book3s_xive.c | 32 ++++
11 files changed, 453 insertions(+), 116 deletions(-)
create mode 100644 arch/powerpc/kvm/book3s_hv_interrupt.c
diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index d0b832cbbec8..00eb5224019c 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -151,6 +151,7 @@ extern s32 patch__call_flush_branch_caches3;
extern s32 patch__flush_count_cache_return;
extern s32 patch__flush_link_stack_return;
extern s32 patch__call_kvm_flush_link_stack;
+extern s32 patch__call_kvm_flush_link_stack_2;
extern s32 patch__memset_nocache, patch__memcpy_nocache;
extern long flush_branch_caches;
@@ -171,7 +172,7 @@ void kvmhv_load_host_pmu(void);
void kvmhv_save_guest_pmu(struct kvm_vcpu *vcpu, bool pmu_in_use);
void kvmhv_load_guest_pmu(struct kvm_vcpu *vcpu);
-int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu);
+void kvmppc_p9_enter_guest(struct kvm_vcpu *vcpu);
long kvmppc_h_set_dabr(struct kvm_vcpu *vcpu, unsigned long dabr);
long kvmppc_h_set_xdabr(struct kvm_vcpu *vcpu, unsigned long dabr,
diff --git a/arch/powerpc/include/asm/kvm_asm.h b/arch/powerpc/include/asm/kvm_asm.h
index a3633560493b..b4f9996bd331 100644
--- a/arch/powerpc/include/asm/kvm_asm.h
+++ b/arch/powerpc/include/asm/kvm_asm.h
@@ -146,7 +146,8 @@
#define KVM_GUEST_MODE_GUEST 1
#define KVM_GUEST_MODE_SKIP 2
#define KVM_GUEST_MODE_GUEST_HV 3
-#define KVM_GUEST_MODE_HOST_HV 4
+#define KVM_GUEST_MODE_GUEST_HV_FAST 4 /* ISA v3.0 with host radix mode */
+#define KVM_GUEST_MODE_HOST_HV 5
#define KVM_INST_FETCH_FAILED -1
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 9bb9bb370b53..7f08f6ed73df 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -153,6 +153,8 @@ static inline bool kvmhv_vcpu_is_radix(struct kvm_vcpu *vcpu)
return radix;
}
+int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu);
+
#define KVM_DEFAULT_HPT_ORDER 24 /* 16MB HPT by default */
#endif
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 45b7610773b1..013e9d8b0754 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -670,6 +670,7 @@ 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)
{
@@ -710,6 +711,7 @@ 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/kernel/security.c b/arch/powerpc/kernel/security.c
index e4e1a94ccf6a..6c37aeed0650 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -430,16 +430,19 @@ device_initcall(stf_barrier_debugfs_init);
static void update_branch_cache_flush(void)
{
- u32 *site;
+ u32 *site, __maybe_unused *site2;
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
site = &patch__call_kvm_flush_link_stack;
+ site2 = &patch__call_kvm_flush_link_stack_2;
// This controls the branch from guest_exit_cont to kvm_flush_link_stack
if (link_stack_flush_type == BRANCH_CACHE_FLUSH_NONE) {
patch_instruction_site(site, ppc_inst(PPC_INST_NOP));
+ patch_instruction_site(site2, ppc_inst(PPC_INST_NOP));
} else {
// Could use HW flush, but that could also flush count cache
patch_branch_site(site, (u64)&kvm_flush_link_stack, BRANCH_SET_LINK);
+ patch_branch_site(site2, (u64)&kvm_flush_link_stack, BRANCH_SET_LINK);
}
#endif
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index cdd119028f64..b94be8c9bad1 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -43,6 +43,9 @@ kvm-objs-$(CONFIG_KVM_E500MC) := $(kvm-e500mc-objs)
kvm-book3s_64-builtin-objs-$(CONFIG_SPAPR_TCE_IOMMU) := \
book3s_64_vio_hv.o
+kvm-book3s_64-objs-y += \
+ book3s_hv_interrupt.o
+
kvm-pr-y := \
fpu.o \
emulate.o \
diff --git a/arch/powerpc/kvm/book3s_64_entry.S b/arch/powerpc/kvm/book3s_64_entry.S
index 6f06b58b1bdd..5fb605dc457c 100644
--- a/arch/powerpc/kvm/book3s_64_entry.S
+++ b/arch/powerpc/kvm/book3s_64_entry.S
@@ -1,10 +1,13 @@
#include <asm/asm-offsets.h>
#include <asm/cache.h>
+#include <asm/code-patching-asm.h>
#include <asm/exception-64s.h>
+#include <asm/export.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_book3s_asm.h>
#include <asm/ppc_asm.h>
#include <asm/reg.h>
+#include <asm/ultravisor-api.h>
/*
* These are branched to from interrupt handlers in exception-64s.S which set
@@ -13,13 +16,24 @@
.global kvmppc_hcall
.balign IFETCH_ALIGN_BYTES
kvmppc_hcall:
+ lbz r10,HSTATE_IN_GUEST(r13)
+ cmpwi r10,KVM_GUEST_MODE_GUEST_HV_FAST
+ beq kvmppc_p9_exit_hcall
ld r10,PACA_EXGEN+EX_R13(r13)
SET_SCRATCH0(r10)
li r10,0xc00
+ li r11,PACA_EXGEN
+ b 1f
.global kvmppc_interrupt
.balign IFETCH_ALIGN_BYTES
kvmppc_interrupt:
+ std r10,HSTATE_SCRATCH0(r13)
+ lbz r10,HSTATE_IN_GUEST(r13)
+ cmpwi r10,KVM_GUEST_MODE_GUEST_HV_FAST
+ beq kvmppc_p9_exit_interrupt
+ ld r10,HSTATE_SCRATCH0(r13)
+ lbz r11,HSTATE_IN_GUEST(r13)
li r11,PACA_EXGEN
cmpdi r10,0x200
bgt+ 1f
@@ -113,3 +127,169 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
GET_SCRATCH0(r13)
HRFI_TO_KERNEL
#endif
+
+/* Stack frame offsets for kvmppc_hv_entry */
+#define SFS 208
+#define STACK_SLOT_VCPU (SFS-8)
+#define STACK_SLOT_NVGPRS (SFS-152) /* 18 gprs */
+
+/*
+ * void kvmppc_p9_enter_guest(struct vcpu *vcpu);
+ *
+ * Enter the guest on a ISAv3.0 or later system where we have exactly
+ * one vcpu per vcore, and both the host and guest are radix, and threads
+ * are set to "indepdent mode".
+ */
+.balign IFETCH_ALIGN_BYTES
+_GLOBAL(kvmppc_p9_enter_guest)
+EXPORT_SYMBOL_GPL(kvmppc_p9_enter_guest)
+ mflr r0
+ std r0, PPC_LR_STKOFF(r1)
+ stdu r1, -SFS(r1)
+
+ std r1, HSTATE_HOST_R1(r13)
+ std r3, STACK_SLOT_VCPU(r1)
+
+ mfcr r4
+ stw r4, SFS+8(r1)
+
+ reg = 14
+ .rept 18
+ std reg, STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
+ reg = reg + 1
+ .endr
+
+ ld r4,VCPU_LR(r3)
+ mtlr r4
+ ld r4,VCPU_CTR(r3)
+ mtctr r4
+ ld r4,VCPU_XER(r3)
+ mtspr SPRN_XER,r4
+
+ ld r1,VCPU_CR(r3)
+
+BEGIN_FTR_SECTION
+ ld r4,VCPU_CFAR(r3)
+ mtspr SPRN_CFAR,r4
+END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
+BEGIN_FTR_SECTION
+ ld r4,VCPU_PPR(r3)
+ mtspr SPRN_PPR,r4
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+ reg = 4
+ .rept 28
+ ld reg, __VCPU_GPR(reg)(r3)
+ reg = reg + 1
+ .endr
+
+ ld r4,VCPU_KVM(r3)
+ lbz r4,KVM_SECURE_GUEST(r4)
+ cmpdi r4,0
+ ld r4,VCPU_GPR(R4)(r3)
+ bne .Lret_to_ultra
+
+ mtcr r1
+
+ ld r0,VCPU_GPR(R0)(r3)
+ ld r1,VCPU_GPR(R1)(r3)
+ ld r2,VCPU_GPR(R2)(r3)
+ ld r3,VCPU_GPR(R3)(r3)
+
+ HRFI_TO_GUEST
+ b .
+
+ /*
+ * Use UV_RETURN ultracall to return control back to the Ultravisor
+ * after processing an hypercall or interrupt that was forwarded
+ * (a.k.a. reflected) to the Hypervisor.
+ *
+ * All registers have already been reloaded except the ucall requires:
+ * R0 = hcall result
+ * R2 = SRR1, so UV can detect a synthesized interrupt (if any)
+ * R3 = UV_RETURN
+ */
+.Lret_to_ultra:
+ mtcr r1
+ ld r1,VCPU_GPR(R1)(r3)
+
+ ld r0,VCPU_GPR(R3)(r3)
+ mfspr r2,SPRN_SRR1
+ LOAD_REG_IMMEDIATE(r3, UV_RETURN)
+ sc 2
+
+/*
+ * kvmppc_p9_exit_hcall and kvmppc_p9_exit_interrupt are branched to from
+ * above if the interrupt was taken for a guest that was entered via
+ * kvmppc_p9_enter_guest().
+ *
+ * This code recovers the host stack and vcpu pointer, saves all GPRs and
+ * CR, LR, CTR, XER as well as guest MSR and NIA into the VCPU, then re-
+ * establishes the host stack and registers to return from the
+ * kvmppc_p9_enter_guest() function.
+ */
+.balign IFETCH_ALIGN_BYTES
+kvmppc_p9_exit_hcall:
+ mfspr r11,SPRN_SRR0
+ mfspr r12,SPRN_SRR1
+ li r10,0xc00
+ std r10,HSTATE_SCRATCH0(r13)
+
+.balign IFETCH_ALIGN_BYTES
+kvmppc_p9_exit_interrupt:
+ std r1,HSTATE_SCRATCH1(r13)
+ std r3,HSTATE_SCRATCH2(r13)
+ ld r1,HSTATE_HOST_R1(r13)
+ ld r3, STACK_SLOT_VCPU(r1)
+
+ std r9,VCPU_CR(r3)
+
+1:
+ std r11,VCPU_PC(r3)
+ std r12,VCPU_MSR(r3)
+
+ reg = 14
+ .rept 18
+ std reg,__VCPU_GPR(reg)(r3)
+ reg = reg + 1
+ .endr
+
+ /* r1, r3, r9-r13 are saved to vcpu by C code */
+ std r0,VCPU_GPR(R0)(r3)
+ std r2,VCPU_GPR(R2)(r3)
+ reg = 4
+ .rept 5
+ std reg,__VCPU_GPR(reg)(r3)
+ reg = reg + 1
+ .endr
+
+ ld r2,PACATOC(r13)
+
+ mflr r4
+ std r4,VCPU_LR(r3)
+ mfspr r4,SPRN_XER
+ std r4,VCPU_XER(r3)
+
+ reg = 14
+ .rept 18
+ ld reg, STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
+ reg = reg + 1
+ .endr
+
+ lwz r4, SFS+8(r1)
+ mtcr r4
+
+ /*
+ * Flush the link stack here, before executing the first blr on the
+ * way out of the guest.
+ *
+ * The link stack won't match coming out of the guest anyway so the
+ * only cost is the flush itself. The call clobbers r0.
+ */
+1: nop
+ patch_site 1b patch__call_kvm_flush_link_stack_2
+
+ addi r1, r1, SFS
+ ld r0, PPC_LR_STKOFF(r1)
+ mtlr r0
+ blr
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 6bf7f5ce4865..a2eafc207407 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1127,7 +1127,7 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
* 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;
@@ -3719,18 +3719,18 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit,
vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
mtspr(SPRN_PSSCR_PR, host_psscr);
-
- /* 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_set_gpr(vcpu, 3, 0);
- trap = 0;
- }
} else {
trap = kvmhv_load_hv_regs_and_go(vcpu, time_limit, lpcr);
}
+ /* H_CEDE has to be handled now, not later */
+ if (trap == BOOK3S_INTERRUPT_SYSCALL &&
+ kvmppc_get_gpr(vcpu, 3) == H_CEDE) {
+ kvmppc_cede(vcpu);
+ kvmppc_set_gpr(vcpu, 3, 0);
+ trap = 0;
+ }
+
vcpu->arch.slb_max = 0;
dec = mfspr(SPRN_DEC);
if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
@@ -4396,6 +4396,7 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu)
r = kvmppc_pseries_do_hcall(vcpu);
trace_kvm_hcall_exit(vcpu, r);
kvmppc_core_prepare_to_enter(vcpu);
+ /* XXX: reflect sc 1 from PR=1 as a syscall to guest? */
} else if (r == RESUME_PAGE_FAULT) {
srcu_idx = srcu_read_lock(&kvm->srcu);
r = kvmppc_book3s_hv_page_fault(vcpu,
diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
new file mode 100644
index 000000000000..8623fc927ed3
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -0,0 +1,208 @@
+#include <linux/kernel.h>
+#include <linux/kvm_host.h>
+#include <asm/asm-prototypes.h>
+#include <asm/dbell.h>
+#include <asm/kvm_ppc.h>
+
+#ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
+static void __start_timing(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
+{
+ struct kvmppc_vcore *vc = vcpu->arch.vcore;
+ u64 tb = mftb() - vc->tb_offset_applied;
+
+ vcpu->arch.cur_activity = next;
+ vcpu->arch.cur_tb_start = tb;
+}
+
+static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
+{
+ struct kvmppc_vcore *vc = vcpu->arch.vcore;
+ struct kvmhv_tb_accumulator *curr;
+ u64 tb = mftb() - vc->tb_offset_applied;
+ u64 prev_tb;
+ u64 delta;
+ u64 seq;
+
+ curr = vcpu->arch.cur_activity;
+ vcpu->arch.cur_activity = next;
+ prev_tb = vcpu->arch.cur_tb_start;
+ vcpu->arch.cur_tb_start = tb;
+
+ if (!curr)
+ return;
+
+ delta = tb - prev_tb;
+
+ seq = curr->seqcount;
+ curr->seqcount = seq + 1;
+ smp_wmb();
+ curr->tb_total += delta;
+ if (seq == 0 || delta < curr->tb_min)
+ curr->tb_min = delta;
+ if (delta > curr->tb_max)
+ curr->tb_max = delta;
+ smp_wmb();
+ curr->seqcount = seq + 2;
+}
+
+#define start_timing(vcpu, next) __start_timing(vcpu, next)
+#define end_timing(vcpu) __start_timing(vcpu, NULL)
+#define accumulate_time(vcpu, next) __accumulate_time(vcpu, next)
+#else
+#define start_timing(vcpu, next) do {} while (0)
+#define end_timing(vcpu) do {} while (0)
+#define accumulate_time(vcpu, next) do {} while (0)
+#endif
+
+static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
+{
+ asm volatile("slbmfev %0,%1" : "=r" (*slbev) : "r" (idx));
+ asm volatile("slbmfee %0,%1" : "=r" (*slbee) : "r" (idx));
+}
+
+static inline void mtslb(unsigned int idx, u64 slbee, u64 slbev)
+{
+ BUG_ON((slbee & 0xfff) != idx);
+
+ asm volatile("slbmte %0,%1" :: "r" (slbev), "r" (slbee));
+}
+
+static inline void slb_invalidate(unsigned int ih)
+{
+ asm volatile("slbia %0" :: "i"(ih));
+}
+
+/*
+ * Malicious or buggy radix guests may have inserted SLB entries
+ * (only 0..3 because radix always runs with UPRT=1), so these must
+ * be cleared here to avoid side-channels. slbmte is used rather
+ * than slbia, as it won't clear cached translations.
+ */
+static void radix_clear_slb(void)
+{
+ u64 slbee, slbev;
+ int i;
+
+ for (i = 0; i < 4; i++) {
+ mfslb(i, &slbee, &slbev);
+ if (unlikely(slbee || slbev)) {
+ slbee = i;
+ slbev = 0;
+ mtslb(i, slbee, slbev);
+ }
+ }
+}
+
+int __kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu)
+{
+ u64 *exsave;
+ unsigned long msr = mfmsr();
+ int trap;
+
+ start_timing(vcpu, &vcpu->arch.rm_entry);
+
+ vcpu->arch.ceded = 0;
+
+ WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
+ WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
+
+ mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
+ mtspr(SPRN_HSRR1, (vcpu->arch.shregs.msr & ~MSR_HV) | MSR_ME);
+
+ accumulate_time(vcpu, &vcpu->arch.guest_time);
+
+ local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_GUEST_HV_FAST;
+ kvmppc_p9_enter_guest(vcpu);
+ // Radix host and guest means host never runs with guest MMU state
+ local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_NONE;
+
+ accumulate_time(vcpu, &vcpu->arch.rm_intr);
+
+ /* Get these from r11/12 and paca exsave */
+ vcpu->arch.shregs.srr0 = mfspr(SPRN_SRR0);
+ vcpu->arch.shregs.srr1 = mfspr(SPRN_SRR1);
+ vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
+ vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
+
+ trap = local_paca->kvm_hstate.scratch0 & ~0x2;
+ if (likely(trap > BOOK3S_INTERRUPT_MACHINE_CHECK)) {
+ exsave = local_paca->exgen;
+ } else if (trap == BOOK3S_INTERRUPT_SYSTEM_RESET) {
+ exsave = local_paca->exnmi;
+ } else { /* trap == 0x200 */
+ exsave = local_paca->exmc;
+ }
+
+ vcpu->arch.regs.gpr[1] = local_paca->kvm_hstate.scratch1;
+ vcpu->arch.regs.gpr[3] = local_paca->kvm_hstate.scratch2;
+ vcpu->arch.regs.gpr[9] = exsave[EX_R9/sizeof(u64)];
+ vcpu->arch.regs.gpr[10] = exsave[EX_R10/sizeof(u64)];
+ vcpu->arch.regs.gpr[11] = exsave[EX_R11/sizeof(u64)];
+ vcpu->arch.regs.gpr[12] = exsave[EX_R12/sizeof(u64)];
+ vcpu->arch.regs.gpr[13] = exsave[EX_R13/sizeof(u64)];
+ vcpu->arch.ppr = exsave[EX_PPR/sizeof(u64)];
+ vcpu->arch.cfar = exsave[EX_CFAR/sizeof(u64)];
+ vcpu->arch.regs.ctr = exsave[EX_CTR/sizeof(u64)];
+
+ vcpu->arch.last_inst = KVM_INST_FETCH_FAILED;
+
+ if (unlikely(trap == BOOK3S_INTERRUPT_MACHINE_CHECK)) {
+ vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
+ vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
+ kvmppc_realmode_machine_check(vcpu);
+
+ } else if (unlikely(trap == BOOK3S_INTERRUPT_HMI)) {
+ kvmppc_realmode_hmi_handler();
+
+ } else if (trap == BOOK3S_INTERRUPT_H_EMUL_ASSIST) {
+ vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
+
+ } else if (trap == BOOK3S_INTERRUPT_H_DATA_STORAGE) {
+ vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
+ vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
+ vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
+
+ } else if (trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
+ vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
+
+ } else if (trap == BOOK3S_INTERRUPT_H_FAC_UNAVAIL) {
+ vcpu->arch.hfscr = mfspr(SPRN_HFSCR);
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ /*
+ * Softpatch interrupt for transactional memory emulation cases
+ * on POWER9 DD2.2. This is early in the guest exit path - we
+ * haven't saved registers or done a treclaim yet.
+ */
+ } else if (trap == BOOK3S_INTERRUPT_HV_SOFTPATCH) {
+ vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
+
+ /*
+ * The cases we want to handle here are those where the guest
+ * is in real suspend mode and is trying to transition to
+ * transactional mode.
+ */
+ if (local_paca->kvm_hstate.fake_suspend &&
+ (vcpu->arch.shregs.msr & MSR_TS_S)) {
+ if (kvmhv_p9_tm_emulation(vcpu)) {
+ /* Could return to guest quickly if handled */
+ /* XXX: can this all be done by the hv exit
+ * handler? May need to adjust hv exit handler.
+ */
+ }
+ }
+#endif
+ }
+
+ radix_clear_slb();
+
+ __mtmsrd(msr, 0);
+
+ accumulate_time(vcpu, &vcpu->arch.rm_exit);
+
+ kvmppc_xive_pull_vcpu(vcpu);
+
+ end_timing(vcpu);
+
+ return trap;
+}
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index eff4437e381c..aa8199c148f2 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -46,7 +46,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
/* Stack frame offsets for kvmppc_hv_entry */
#define SFS 208
#define STACK_SLOT_TRAP (SFS-4)
-#define STACK_SLOT_SHORT_PATH (SFS-8)
#define STACK_SLOT_TID (SFS-16)
#define STACK_SLOT_PSSCR (SFS-24)
#define STACK_SLOT_PID (SFS-32)
@@ -994,9 +993,6 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
no_xive:
#endif /* CONFIG_KVM_XICS */
- li r0, 0
- stw r0, STACK_SLOT_SHORT_PATH(r1)
-
deliver_guest_interrupt: /* r4 = vcpu, r13 = paca */
/* Check if we can deliver an external or decrementer interrupt now */
ld r0, VCPU_PENDING_EXC(r4)
@@ -1121,97 +1117,6 @@ ret_to_ultra:
ld r4, VCPU_GPR(R4)(r4)
sc 2
-/*
- * Enter the guest on a P9 or later system where we have exactly
- * one vcpu per vcore and we don't need to go to real mode
- * (which implies that host and guest are both using radix MMU mode).
- * r3 = vcpu pointer
- * Most SPRs and all the VSRs have been loaded already.
- */
-_GLOBAL(__kvmhv_vcpu_entry_p9)
-EXPORT_SYMBOL_GPL(__kvmhv_vcpu_entry_p9)
- mflr r0
- std r0, PPC_LR_STKOFF(r1)
- stdu r1, -SFS(r1)
-
- li r0, 1
- stw r0, STACK_SLOT_SHORT_PATH(r1)
-
- std r3, HSTATE_KVM_VCPU(r13)
- mfcr r4
- stw r4, SFS+8(r1)
-
- std r1, HSTATE_HOST_R1(r13)
-
- reg = 14
- .rept 18
- std reg, STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
- reg = reg + 1
- .endr
-
- reg = 14
- .rept 18
- ld reg, __VCPU_GPR(reg)(r3)
- reg = reg + 1
- .endr
-
- mfmsr r10
- std r10, HSTATE_HOST_MSR(r13)
-
- mr r4, r3
- b fast_guest_entry_c
-guest_exit_short_path:
- /*
- * Malicious or buggy radix guests may have inserted SLB entries
- * (only 0..3 because radix always runs with UPRT=1), so these must
- * be cleared here to avoid side-channels. slbmte is used rather
- * than slbia, as it won't clear cached translations.
- */
- li r0,0
- slbmte r0,r0
- li r4,1
- slbmte r0,r4
- li r4,2
- slbmte r0,r4
- li r4,3
- slbmte r0,r4
-
- li r0, KVM_GUEST_MODE_NONE
- stb r0, HSTATE_IN_GUEST(r13)
-
- reg = 14
- .rept 18
- std reg, __VCPU_GPR(reg)(r9)
- reg = reg + 1
- .endr
-
- reg = 14
- .rept 18
- ld reg, STACK_SLOT_NVGPRS + ((reg - 14) * 8)(r1)
- reg = reg + 1
- .endr
-
- lwz r4, SFS+8(r1)
- mtcr r4
-
- mr r3, r12 /* trap number */
-
- addi r1, r1, SFS
- ld r0, PPC_LR_STKOFF(r1)
- mtlr r0
-
- /* If we are in real mode, do a rfid to get back to the caller */
- mfmsr r4
- andi. r5, r4, MSR_IR
- bnelr
- rldicl r5, r4, 64 - MSR_TS_S_LG, 62 /* extract TS field */
- mtspr SPRN_SRR0, r0
- ld r10, HSTATE_HOST_MSR(r13)
- rldimi r10, r5, MSR_TS_S_LG, 63 - MSR_TS_T_LG
- mtspr SPRN_SRR1, r10
- RFI_TO_KERNEL
- b .
-
secondary_too_late:
li r12, 0
stw r12, STACK_SLOT_TRAP(r1)
@@ -1466,17 +1371,11 @@ guest_exit_cont: /* r9 = vcpu, r12 = trap, r13 = paca */
#endif /* CONFIG_KVM_XICS */
/*
- * Possibly flush the link stack here, before we do a blr in
- * guest_exit_short_path.
+ * Possibly flush the link stack here.
*/
1: nop
patch_site 1b patch__call_kvm_flush_link_stack
- /* If we came in through the P9 short path, go back out to C now */
- lwz r0, STACK_SLOT_SHORT_PATH(r1)
- cmpwi r0, 0
- bne guest_exit_short_path
-
/* For hash guest, read the guest SLB and save it away */
ld r5, VCPU_KVM(r9)
lbz r0, KVM_RADIX(r5)
@@ -1529,7 +1428,12 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
* This is probably harmless but is unexpected.
*/
stw r5,VCPU_SLB_MAX(r9)
- /* Sanitise radix guest SLB, see guest_exit_short_path comment. */
+ /*
+ * Malicious or buggy radix guests may have inserted SLB entries
+ * (only 0..3 because radix always runs with UPRT=1), so these must
+ * be cleared here to avoid side-channels. slbmte is used rather
+ * than slbia, as it won't clear cached translations.
+ */
li r0,0
slbmte r0,r0
li r4,1
@@ -3331,7 +3235,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
mtspr SPRN_CIABR, r0
mtspr SPRN_DAWRX0, r0
- /* Clear hash and radix guest SLB, see guest_exit_short_path comment. */
+ /* Clear hash and radix guest SLB. */
slbmte r0, r0
PPC_SLBIA(6)
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c
index 30dfeac731c6..22a3be0aafa1 100644
--- a/arch/powerpc/kvm/book3s_xive.c
+++ b/arch/powerpc/kvm/book3s_xive.c
@@ -127,6 +127,38 @@ 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;
+
+ /*
+ * Sould 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_readw(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_pushed = 0;
+ vcpu->arch.xive_saved_state.lsmfb = 0;
+ vcpu->arch.xive_saved_state.ack = 0xff;
+ 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
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