* [PATCH v7 1/4] KVM: x86: Simple kvm_x86_ops->queue_exception parameter
2017-06-29 3:01 [PATCH v7 0/4] KVM: async_pf: Fix async pf exception injection Wanpeng Li
@ 2017-06-29 3:01 ` Wanpeng Li
2017-06-29 3:01 ` [PATCH v7 2/4] KVM: async_pf: Add L1 guest async_pf #PF vmexit handler Wanpeng Li
` (3 subsequent siblings)
4 siblings, 0 replies; 11+ messages in thread
From: Wanpeng Li @ 2017-06-29 3:01 UTC (permalink / raw)
To: linux-kernel, kvm; +Cc: Paolo Bonzini, Radim Krčmář, Wanpeng Li
From: Wanpeng Li <wanpeng.li@hotmail.com>
This patch removes all arguments except the first in kvm_x86_ops->queue_exception
since they can extract the arguments from vcpu->arch.exception themselves, do the
same in nested_{vmx,svm}_check_exception.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
arch/x86/include/asm/kvm_host.h | 4 +---
arch/x86/kvm/svm.c | 8 +++++---
arch/x86/kvm/vmx.c | 8 +++++---
arch/x86/kvm/x86.c | 5 +----
4 files changed, 12 insertions(+), 13 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 695605e..1f01bfb 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -948,9 +948,7 @@ struct kvm_x86_ops {
unsigned char *hypercall_addr);
void (*set_irq)(struct kvm_vcpu *vcpu);
void (*set_nmi)(struct kvm_vcpu *vcpu);
- void (*queue_exception)(struct kvm_vcpu *vcpu, unsigned nr,
- bool has_error_code, u32 error_code,
- bool reinject);
+ void (*queue_exception)(struct kvm_vcpu *vcpu);
void (*cancel_injection)(struct kvm_vcpu *vcpu);
int (*interrupt_allowed)(struct kvm_vcpu *vcpu);
int (*nmi_allowed)(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index ba9891a..e1f8e89 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -631,11 +631,13 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
svm_set_interrupt_shadow(vcpu, 0);
}
-static void svm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
- bool has_error_code, u32 error_code,
- bool reinject)
+static void svm_queue_exception(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
+ unsigned nr = vcpu->arch.exception.nr;
+ bool has_error_code = vcpu->arch.exception.has_error_code;
+ bool reinject = vcpu->arch.exception.reinject;
+ u32 error_code = vcpu->arch.exception.error_code;
/*
* If we are within a nested VM we'd better #VMEXIT and let the guest
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ca5d2b9..df825bb 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2431,11 +2431,13 @@ static int nested_vmx_check_exception(struct kvm_vcpu *vcpu, unsigned nr)
return 1;
}
-static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
- bool has_error_code, u32 error_code,
- bool reinject)
+static void vmx_queue_exception(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
+ unsigned nr = vcpu->arch.exception.nr;
+ bool has_error_code = vcpu->arch.exception.has_error_code;
+ bool reinject = vcpu->arch.exception.reinject;
+ u32 error_code = vcpu->arch.exception.error_code;
u32 intr_info = nr | INTR_INFO_VALID_MASK;
if (!reinject && is_guest_mode(vcpu) &&
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0e846f0..7511c0a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6347,10 +6347,7 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool req_int_win)
kvm_update_dr7(vcpu);
}
- kvm_x86_ops->queue_exception(vcpu, vcpu->arch.exception.nr,
- vcpu->arch.exception.has_error_code,
- vcpu->arch.exception.error_code,
- vcpu->arch.exception.reinject);
+ kvm_x86_ops->queue_exception(vcpu);
return 0;
}
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v7 2/4] KVM: async_pf: Add L1 guest async_pf #PF vmexit handler
2017-06-29 3:01 [PATCH v7 0/4] KVM: async_pf: Fix async pf exception injection Wanpeng Li
2017-06-29 3:01 ` [PATCH v7 1/4] KVM: x86: Simple kvm_x86_ops->queue_exception parameter Wanpeng Li
@ 2017-06-29 3:01 ` Wanpeng Li
2017-07-12 21:44 ` Radim Krčmář
2017-06-29 3:02 ` [PATCH v7 3/4] KVM: async_pf: Force a nested vmexit if the injected #PF is async_pf Wanpeng Li
` (2 subsequent siblings)
4 siblings, 1 reply; 11+ messages in thread
From: Wanpeng Li @ 2017-06-29 3:01 UTC (permalink / raw)
To: linux-kernel, kvm; +Cc: Paolo Bonzini, Radim Krčmář, Wanpeng Li
From: Wanpeng Li <wanpeng.li@hotmail.com>
This patch adds the L1 guest async page fault #PF vmexit handler, such
#PF is converted into vmexit from L2 to L1 on #PF which is then handled
by L1 similar to ordinary async page fault.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/mmu.c | 33 +++++++++++++++++++++++++++++++++
arch/x86/kvm/mmu.h | 2 ++
arch/x86/kvm/svm.c | 36 +++++-------------------------------
arch/x86/kvm/vmx.c | 12 +++++-------
5 files changed, 46 insertions(+), 38 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 1f01bfb..e20d8a8 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -645,6 +645,7 @@ struct kvm_vcpu_arch {
u64 msr_val;
u32 id;
bool send_user_only;
+ u32 host_apf_reason;
} apf;
/* OSVW MSRs (AMD only) */
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index cb82259..4a7dc00 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -46,6 +46,7 @@
#include <asm/io.h>
#include <asm/vmx.h>
#include <asm/kvm_page_track.h>
+#include "trace.h"
/*
* When setting this variable to true it enables Two-Dimensional-Paging
@@ -3736,6 +3737,38 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
return false;
}
+int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
+ u64 fault_address)
+{
+ int r = 1;
+
+ switch (vcpu->arch.apf.host_apf_reason) {
+ default:
+ /* TDP won't cause page fault directly */
+ WARN_ON_ONCE(tdp_enabled);
+ trace_kvm_page_fault(fault_address, error_code);
+
+ if (kvm_event_needs_reinjection(vcpu))
+ kvm_mmu_unprotect_page_virt(vcpu, fault_address);
+ r = kvm_mmu_page_fault(vcpu, fault_address, error_code, NULL, 0);
+ break;
+ case KVM_PV_REASON_PAGE_NOT_PRESENT:
+ vcpu->arch.apf.host_apf_reason = 0;
+ local_irq_disable();
+ kvm_async_pf_task_wait(fault_address);
+ local_irq_enable();
+ break;
+ case KVM_PV_REASON_PAGE_READY:
+ vcpu->arch.apf.host_apf_reason = 0;
+ local_irq_disable();
+ kvm_async_pf_task_wake(fault_address);
+ local_irq_enable();
+ break;
+ }
+ return r;
+}
+EXPORT_SYMBOL_GPL(kvm_handle_page_fault);
+
static bool
check_hugepage_cache_consistency(struct kvm_vcpu *vcpu, gfn_t gfn, int level)
{
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 330bf3a..2ae88f0 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -77,6 +77,8 @@ void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu);
void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
bool accessed_dirty);
bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu);
+int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
+ u64 fault_address);
static inline unsigned int kvm_mmu_available_pages(struct kvm *kvm)
{
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index e1f8e89..8f263bf 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -192,7 +192,6 @@ struct vcpu_svm {
unsigned int3_injected;
unsigned long int3_rip;
- u32 apf_reason;
/* cached guest cpuid flags for faster access */
bool nrips_enabled : 1;
@@ -2071,34 +2070,9 @@ static void svm_set_dr7(struct kvm_vcpu *vcpu, unsigned long value)
static int pf_interception(struct vcpu_svm *svm)
{
u64 fault_address = svm->vmcb->control.exit_info_2;
- u64 error_code;
- int r = 1;
+ u64 error_code = svm->vmcb->control.exit_info_1;
- switch (svm->apf_reason) {
- default:
- error_code = svm->vmcb->control.exit_info_1;
-
- trace_kvm_page_fault(fault_address, error_code);
- if (!npt_enabled && kvm_event_needs_reinjection(&svm->vcpu))
- kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address);
- r = kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code,
- svm->vmcb->control.insn_bytes,
- svm->vmcb->control.insn_len);
- break;
- case KVM_PV_REASON_PAGE_NOT_PRESENT:
- svm->apf_reason = 0;
- local_irq_disable();
- kvm_async_pf_task_wait(fault_address);
- local_irq_enable();
- break;
- case KVM_PV_REASON_PAGE_READY:
- svm->apf_reason = 0;
- local_irq_disable();
- kvm_async_pf_task_wake(fault_address);
- local_irq_enable();
- break;
- }
- return r;
+ return kvm_handle_page_fault(&svm->vcpu, error_code, fault_address);
}
static int db_interception(struct vcpu_svm *svm)
@@ -2551,7 +2525,7 @@ static int nested_svm_exit_special(struct vcpu_svm *svm)
break;
case SVM_EXIT_EXCP_BASE + PF_VECTOR:
/* When we're shadowing, trap PFs, but not async PF */
- if (!npt_enabled && svm->apf_reason == 0)
+ if (!npt_enabled && svm->vcpu.arch.apf.host_apf_reason == 0)
return NESTED_EXIT_HOST;
break;
default:
@@ -2594,7 +2568,7 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
vmexit = NESTED_EXIT_DONE;
/* async page fault always cause vmexit */
else if ((exit_code == SVM_EXIT_EXCP_BASE + PF_VECTOR) &&
- svm->apf_reason != 0)
+ svm->vcpu.arch.apf.host_apf_reason != 0)
vmexit = NESTED_EXIT_DONE;
break;
}
@@ -4891,7 +4865,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu)
/* if exit due to PF check for async PF */
if (svm->vmcb->control.exit_code == SVM_EXIT_EXCP_BASE + PF_VECTOR)
- svm->apf_reason = kvm_read_and_reset_pf_reason();
+ svm->vcpu.arch.apf.host_apf_reason = kvm_read_and_reset_pf_reason();
if (npt_enabled) {
vcpu->arch.regs_avail &= ~(1 << VCPU_EXREG_PDPTR);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index df825bb..d20f794 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5648,14 +5648,8 @@ static int handle_exception(struct kvm_vcpu *vcpu)
}
if (is_page_fault(intr_info)) {
- /* EPT won't cause page fault directly */
- BUG_ON(enable_ept);
cr2 = vmcs_readl(EXIT_QUALIFICATION);
- trace_kvm_page_fault(cr2, error_code);
-
- if (kvm_event_needs_reinjection(vcpu))
- kvm_mmu_unprotect_page_virt(vcpu, cr2);
- return kvm_mmu_page_fault(vcpu, cr2, error_code, NULL, 0);
+ return kvm_handle_page_fault(vcpu, error_code, cr2);
}
ex_no = intr_info & INTR_INFO_VECTOR_MASK;
@@ -8602,6 +8596,10 @@ static void vmx_complete_atomic_exit(struct vcpu_vmx *vmx)
vmx->exit_intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
exit_intr_info = vmx->exit_intr_info;
+ /* if exit due to PF check for async PF */
+ if (is_page_fault(exit_intr_info))
+ vmx->vcpu.arch.apf.host_apf_reason = kvm_read_and_reset_pf_reason();
+
/* Handle machine checks before interrupts are enabled */
if (is_machine_check(exit_intr_info))
kvm_machine_check();
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH v7 2/4] KVM: async_pf: Add L1 guest async_pf #PF vmexit handler
2017-06-29 3:01 ` [PATCH v7 2/4] KVM: async_pf: Add L1 guest async_pf #PF vmexit handler Wanpeng Li
@ 2017-07-12 21:44 ` Radim Krčmář
2017-07-13 1:34 ` Wanpeng Li
2017-07-13 15:29 ` Radim Krčmář
0 siblings, 2 replies; 11+ messages in thread
From: Radim Krčmář @ 2017-07-12 21:44 UTC (permalink / raw)
To: Wanpeng Li; +Cc: linux-kernel, kvm, Paolo Bonzini, Wanpeng Li
2017-06-28 20:01-0700, Wanpeng Li:
> From: Wanpeng Li <wanpeng.li@hotmail.com>
>
> This patch adds the L1 guest async page fault #PF vmexit handler, such
> #PF is converted into vmexit from L2 to L1 on #PF which is then handled
> by L1 similar to ordinary async page fault.
>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Radim Krčmář <rkrcmar@redhat.com>
> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
> ---
This patch breaks SVM, so I've taken the series off kvm/queue for now;
I'll look into it tomorrow. The error is:
BUG: unable to handle kernel paging request at ffffffffc0735ad2
IP: report_bug+0x94/0x120
PGD 43e14067
P4D 43e14067
PUD 43e16067
PMD 2164bf067
PTE 80000002181fc161
Oops: 0003 [#1] SMP
Modules linked in: kvm_amd(OE) kvm(OE) irqbypass(E) xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack libcrc32c tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables sunrpc snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec_hdmi snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device snd_pcm ppdev joydev parport_serial parport_pc snd_timer parport k10temp sky2 snd shpchp sp5100_tco acpi_cpufreq wmi soundcore i2c_piix4 amdkfd amd_iommu_v2 radeon i2c_algo_bit drm_kms_helper uas serio_raw usb_storage ttm pata_atiixp drm ata_generic pata_acpi pata_jmicron [last unloaded: irqbypass]
CPU: 3 PID: 1868 Comm: CPU 0/KVM Tainted: G OE 4.12.0+ #1
Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS 080014 03/07/2008
task: ffff8bcbe3f1b140 task.stack: ffffabb481970000
RIP: 0010:report_bug+0x94/0x120
RSP: 0018:ffffabb481973a70 EFLAGS: 00010202
RAX: 0000000000000907 RBX: ffffabb481973bd8 RCX: ffffffffc0735ac8
RDX: 0000000000000001 RSI: 0000000000000ed0 RDI: 0000000000000001
RBP: ffffabb481973a90 R08: 0000000000000001 R09: 7f9f279200000000
R10: ffffabb4819739d0 R11: 0000000000000000 R12: ffffffffc07023d0
R13: ffffffffc0733078 R14: 0000000000000004 R15: ffffabb481973bd8
FS: 0000000000000000(0000) GS:ffff8bcbe7400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffc0735ad2 CR3: 00000002189d7000 CR4: 00000000000006e0
Call Trace:
? kvm_handle_page_fault+0x1f0/0x200 [kvm]
fixup_bug+0x2e/0x50
do_trap+0x119/0x150
do_error_trap+0xa3/0x160
? kvm_handle_page_fault+0x1f0/0x200 [kvm]
? trace_hardirqs_off_thunk+0x1a/0x1c
do_invalid_op+0x20/0x30
invalid_op+0x1e/0x30
RIP: 0010:kvm_handle_page_fault+0x1f0/0x200 [kvm]
RSP: 0018:ffffabb481973c80 EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff8bcbd7550000 RCX: 0000000000000000
RDX: 00000000fffffff0 RSI: 0000000000000014 RDI: ffff8bcbd7550000
RBP: ffffabb481973ca0 R08: 0000000000000001 R09: 27624b3d00000000
R10: ffffabb481973ca8 R11: ffff8bcbe3fb25f0 R12: 00000000fffffff0
R13: 0000000000000014 R14: ffff8bcbd7550000 R15: ffff8bcbd7550000
pf_interception+0x20/0x30 [kvm_amd]
handle_exit+0x213/0xbb0 [kvm_amd]
kvm_arch_vcpu_ioctl_run+0x7f1/0x1ae0 [kvm]
kvm_vcpu_ioctl+0x2ac/0x6f0 [kvm]
? kvm_vcpu_ioctl+0x2ac/0x6f0 [kvm]
? sched_clock+0x9/0x10
? debug_lockdep_rcu_enabled+0x1d/0x30
do_vfs_ioctl+0xa6/0x6c0
SyS_ioctl+0x79/0x90
entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x7fabf6d815c7
RSP: 002b:00007fabe87e77c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000010000 RCX: 00007fabf6d815c7
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000010
RBP: 000055a7cb502fe0 R08: 000055a7cb51e410 R09: 000055a7cb509390
R10: 000055a7cdb01000 R11: 0000000000000246 R12: 000055a7cdace0a6
R13: 0000000000000000 R14: 00007fac00621000 R15: 000055a7cdace000
Code: 74 59 0f b7 41 0a 4c 63 69 04 0f b7 71 08 89 c7 49 01 cd 83 e7 01 a8 02 74 15 66 85 ff 74 10 a8 04 ba 01 00 00 00 75 26 83 c8 04 <66> 89 41 0a 66 85 ff 74 49 0f b6 49 0b 4c 89 e2 45 31 c9 49 89
RIP: report_bug+0x94/0x120 RSP: ffffabb481973a70
CR2: ffffffffc0735ad2
---[ end trace aec3a1f15664a4af ]---
BUG: sleeping function called from invalid context at ./include/linux/percpu-rwsem.h:33
in_atomic(): 0, irqs_disabled(): 1, pid: 1868, name: CPU 0/KVM
INFO: lockdep is turned off.
irq event stamp: 1868
hardirqs last enabled at (1867): [<ffffffffa398eaab>] restore_regs_and_iret+0x0/0x1d
hardirqs last disabled at (1868): [<ffffffffa398f7dc>] error_entry+0x7c/0xd0
softirqs last enabled at (1834): [<ffffffffa3992f62>] __do_softirq+0x382/0x4ed
softirqs last disabled at (1817): [<ffffffffa30b9a2f>] irq_exit+0x10f/0x120
CPU: 3 PID: 1868 Comm: CPU 0/KVM Tainted: G D OE 4.12.0+ #1
Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS 080014 03/07/2008
Call Trace:
dump_stack+0x8e/0xcd
___might_sleep+0x164/0x250
__might_sleep+0x4a/0x80
exit_signals+0x33/0x240
do_exit+0xb4/0xd20
? SyS_ioctl+0x79/0x90
rewind_stack_do_exit+0x17/0x20
RIP: 0033:0x7fabf6d815c7
RSP: 002b:00007fabe87e77c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000010000 RCX: 00007fabf6d815c7
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000010
RBP: 000055a7cb502fe0 R08: 000055a7cb51e410 R09: 000055a7cb509390
R10: 000055a7cdb01000 R11: 0000000000000246 R12: 000055a7cdace0a6
R13: 0000000000000000 R14: 00007fac00621000 R15: 000055a7cdace000
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v7 2/4] KVM: async_pf: Add L1 guest async_pf #PF vmexit handler
2017-07-12 21:44 ` Radim Krčmář
@ 2017-07-13 1:34 ` Wanpeng Li
2017-07-13 15:29 ` Radim Krčmář
1 sibling, 0 replies; 11+ messages in thread
From: Wanpeng Li @ 2017-07-13 1:34 UTC (permalink / raw)
To: Radim Krčmář; +Cc: linux-kernel, kvm, Paolo Bonzini, Wanpeng Li
2017-07-13 5:44 GMT+08:00 Radim Krčmář <rkrcmar@redhat.com>:
> 2017-06-28 20:01-0700, Wanpeng Li:
>> From: Wanpeng Li <wanpeng.li@hotmail.com>
>>
>> This patch adds the L1 guest async page fault #PF vmexit handler, such
>> #PF is converted into vmexit from L2 to L1 on #PF which is then handled
>> by L1 similar to ordinary async page fault.
>>
>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>> Cc: Radim Krčmář <rkrcmar@redhat.com>
>> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
>> ---
>
> This patch breaks SVM, so I've taken the series off kvm/queue for now;
> I'll look into it tomorrow.
Thanks for the help. :)
Regards,
Wanpeng Li
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH v7 2/4] KVM: async_pf: Add L1 guest async_pf #PF vmexit handler
2017-07-12 21:44 ` Radim Krčmář
2017-07-13 1:34 ` Wanpeng Li
@ 2017-07-13 15:29 ` Radim Krčmář
2017-07-14 1:40 ` Wanpeng Li
1 sibling, 1 reply; 11+ messages in thread
From: Radim Krčmář @ 2017-07-13 15:29 UTC (permalink / raw)
To: Wanpeng Li; +Cc: linux-kernel, kvm, Paolo Bonzini, Wanpeng Li
2017-07-12 23:44+0200, Radim Krčmář:
> 2017-06-28 20:01-0700, Wanpeng Li:
> > From: Wanpeng Li <wanpeng.li@hotmail.com>
> >
> > This patch adds the L1 guest async page fault #PF vmexit handler, such
> > #PF is converted into vmexit from L2 to L1 on #PF which is then handled
> > by L1 similar to ordinary async page fault.
> >
> > Cc: Paolo Bonzini <pbonzini@redhat.com>
> > Cc: Radim Krčmář <rkrcmar@redhat.com>
> > Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
> > ---
>
> This patch breaks SVM, so I've taken the series off kvm/queue for now;
The error is triggered by 'WARN_ON_ONCE(tdp_enabled);', because
pf_interception() handles both cases. (The bizzare part is that it
doesn't warn.)
I think this hunk on top of the patch would be good. It makes the
WARN_ON_ONCE specific to VMX and also preserves the parameters that SVM
had before.
(Passes basic tests, haven't done the nested async_pf test yet.)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index f37c0307dcb0..338cb4c8cbb9 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3782,17 +3782,16 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
}
int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
- u64 fault_address)
+ u64 fault_address, char *insn, int insn_len,
+ bool need_unprotect)
{
int r = 1;
switch (vcpu->arch.apf.host_apf_reason) {
default:
- /* TDP won't cause page fault directly */
- WARN_ON_ONCE(tdp_enabled);
trace_kvm_page_fault(fault_address, error_code);
- if (kvm_event_needs_reinjection(vcpu))
+ if (need_unprotect && kvm_event_needs_reinjection(vcpu))
kvm_mmu_unprotect_page_virt(vcpu, fault_address);
r = kvm_mmu_page_fault(vcpu, fault_address, error_code, NULL, 0);
break;
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 270d9adaa039..d7d248a000dd 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -78,7 +78,8 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
bool accessed_dirty);
bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu);
int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
- u64 fault_address);
+ u64 fault_address, char *insn, int insn_len,
+ bool need_unprotect);
static inline unsigned int kvm_mmu_available_pages(struct kvm *kvm)
{
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 659b610c4711..fb23497cf915 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2123,7 +2123,9 @@ static int pf_interception(struct vcpu_svm *svm)
u64 fault_address = svm->vmcb->control.exit_info_2;
u64 error_code = svm->vmcb->control.exit_info_1;
- return kvm_handle_page_fault(&svm->vcpu, error_code, fault_address);
+ return kvm_handle_page_fault(&svm->vcpu, error_code, fault_address,
+ svm->vmcb->control.insn_bytes,
+ svm->vmcb->control.insn_len, !npt_enabled);
}
static int db_interception(struct vcpu_svm *svm)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ab33eace4f66..2e8cfb2f1371 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5699,7 +5699,10 @@ static int handle_exception(struct kvm_vcpu *vcpu)
if (is_page_fault(intr_info)) {
cr2 = vmcs_readl(EXIT_QUALIFICATION);
- return kvm_handle_page_fault(vcpu, error_code, cr2);
+ /* TDP won't cause page fault directly */
+ WARN_ON_ONCE(!vcpu->arch.apf.host_apf_reason && tdp_enabled);
+ return kvm_handle_page_fault(vcpu, error_code, cr2, NULL, 0,
+ true);
}
ex_no = intr_info & INTR_INFO_VECTOR_MASK;
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH v7 2/4] KVM: async_pf: Add L1 guest async_pf #PF vmexit handler
2017-07-13 15:29 ` Radim Krčmář
@ 2017-07-14 1:40 ` Wanpeng Li
0 siblings, 0 replies; 11+ messages in thread
From: Wanpeng Li @ 2017-07-14 1:40 UTC (permalink / raw)
To: Radim Krčmář; +Cc: linux-kernel, kvm, Paolo Bonzini, Wanpeng Li
2017-07-13 23:29 GMT+08:00 Radim Krčmář <rkrcmar@redhat.com>:
> 2017-07-12 23:44+0200, Radim Krčmář:
>> 2017-06-28 20:01-0700, Wanpeng Li:
>> > From: Wanpeng Li <wanpeng.li@hotmail.com>
>> >
>> > This patch adds the L1 guest async page fault #PF vmexit handler, such
>> > #PF is converted into vmexit from L2 to L1 on #PF which is then handled
>> > by L1 similar to ordinary async page fault.
>> >
>> > Cc: Paolo Bonzini <pbonzini@redhat.com>
>> > Cc: Radim Krčmář <rkrcmar@redhat.com>
>> > Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
>> > ---
>>
>> This patch breaks SVM, so I've taken the series off kvm/queue for now;
>
> The error is triggered by 'WARN_ON_ONCE(tdp_enabled);', because
> pf_interception() handles both cases. (The bizzare part is that it
> doesn't warn.)
>
> I think this hunk on top of the patch would be good. It makes the
Thanks Radim! The work is really appreciated. :)
> WARN_ON_ONCE specific to VMX and also preserves the parameters that SVM
> had before.
I replace the tdp_enabled by enable_ept in VMX since there is a
warning: "tdp_enabled" in [kvm-intel.ko] undefined! Btw, I just sent
out v8, hope both
the v8 and vm86 stuff can catch the end of the merge window. :)
Regards,
Wanpeng Li
>
> (Passes basic tests, haven't done the nested async_pf test yet.)
>
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index f37c0307dcb0..338cb4c8cbb9 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -3782,17 +3782,16 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
> }
>
> int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
> - u64 fault_address)
> + u64 fault_address, char *insn, int insn_len,
> + bool need_unprotect)
> {
> int r = 1;
>
> switch (vcpu->arch.apf.host_apf_reason) {
> default:
> - /* TDP won't cause page fault directly */
> - WARN_ON_ONCE(tdp_enabled);
> trace_kvm_page_fault(fault_address, error_code);
>
> - if (kvm_event_needs_reinjection(vcpu))
> + if (need_unprotect && kvm_event_needs_reinjection(vcpu))
> kvm_mmu_unprotect_page_virt(vcpu, fault_address);
> r = kvm_mmu_page_fault(vcpu, fault_address, error_code, NULL, 0);
> break;
> diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
> index 270d9adaa039..d7d248a000dd 100644
> --- a/arch/x86/kvm/mmu.h
> +++ b/arch/x86/kvm/mmu.h
> @@ -78,7 +78,8 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
> bool accessed_dirty);
> bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu);
> int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
> - u64 fault_address);
> + u64 fault_address, char *insn, int insn_len,
> + bool need_unprotect);
>
> static inline unsigned int kvm_mmu_available_pages(struct kvm *kvm)
> {
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 659b610c4711..fb23497cf915 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -2123,7 +2123,9 @@ static int pf_interception(struct vcpu_svm *svm)
> u64 fault_address = svm->vmcb->control.exit_info_2;
> u64 error_code = svm->vmcb->control.exit_info_1;
>
> - return kvm_handle_page_fault(&svm->vcpu, error_code, fault_address);
> + return kvm_handle_page_fault(&svm->vcpu, error_code, fault_address,
> + svm->vmcb->control.insn_bytes,
> + svm->vmcb->control.insn_len, !npt_enabled);
> }
>
> static int db_interception(struct vcpu_svm *svm)
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index ab33eace4f66..2e8cfb2f1371 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -5699,7 +5699,10 @@ static int handle_exception(struct kvm_vcpu *vcpu)
>
> if (is_page_fault(intr_info)) {
> cr2 = vmcs_readl(EXIT_QUALIFICATION);
> - return kvm_handle_page_fault(vcpu, error_code, cr2);
> + /* TDP won't cause page fault directly */
> + WARN_ON_ONCE(!vcpu->arch.apf.host_apf_reason && tdp_enabled);
> + return kvm_handle_page_fault(vcpu, error_code, cr2, NULL, 0,
> + true);
> }
>
> ex_no = intr_info & INTR_INFO_VECTOR_MASK;
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH v7 3/4] KVM: async_pf: Force a nested vmexit if the injected #PF is async_pf
2017-06-29 3:01 [PATCH v7 0/4] KVM: async_pf: Fix async pf exception injection Wanpeng Li
2017-06-29 3:01 ` [PATCH v7 1/4] KVM: x86: Simple kvm_x86_ops->queue_exception parameter Wanpeng Li
2017-06-29 3:01 ` [PATCH v7 2/4] KVM: async_pf: Add L1 guest async_pf #PF vmexit handler Wanpeng Li
@ 2017-06-29 3:02 ` Wanpeng Li
2017-06-29 3:02 ` [PATCH v7 4/4] KVM: async_pf: Let host know whether the guest support delivery async_pf as #PF vmexit Wanpeng Li
2017-06-29 7:13 ` [PATCH v7 0/4] KVM: async_pf: Fix async pf exception injection Wanpeng Li
4 siblings, 0 replies; 11+ messages in thread
From: Wanpeng Li @ 2017-06-29 3:02 UTC (permalink / raw)
To: linux-kernel, kvm; +Cc: Paolo Bonzini, Radim Krčmář, Wanpeng Li
From: Wanpeng Li <wanpeng.li@hotmail.com>
Add an nested_apf field to vcpu->arch.exception to identify an async page
fault, and constructs the expected vm-exit information fields. Force a
nested VM exit from nested_vmx_check_exception() if the injected #PF is
async page fault.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
arch/x86/include/asm/kvm_emulate.h | 1 +
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/svm.c | 16 ++++++++++------
arch/x86/kvm/vmx.c | 17 ++++++++++++++---
arch/x86/kvm/x86.c | 9 ++++++++-
5 files changed, 35 insertions(+), 10 deletions(-)
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index 722d0e5..fde36f1 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -23,6 +23,7 @@ struct x86_exception {
u16 error_code;
bool nested_page_fault;
u64 address; /* cr2 or nested page fault gpa */
+ u8 async_page_fault;
};
/*
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e20d8a8..71aef4b 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -545,6 +545,7 @@ struct kvm_vcpu_arch {
bool reinject;
u8 nr;
u32 error_code;
+ u8 nested_apf;
} exception;
struct kvm_queued_interrupt {
@@ -646,6 +647,7 @@ struct kvm_vcpu_arch {
u32 id;
bool send_user_only;
u32 host_apf_reason;
+ unsigned long nested_apf_token;
} apf;
/* OSVW MSRs (AMD only) */
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 8f263bf..49cdb8e 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2367,15 +2367,19 @@ static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr,
if (!is_guest_mode(&svm->vcpu))
return 0;
+ vmexit = nested_svm_intercept(svm);
+ if (vmexit != NESTED_EXIT_DONE)
+ return 0;
+
svm->vmcb->control.exit_code = SVM_EXIT_EXCP_BASE + nr;
svm->vmcb->control.exit_code_hi = 0;
svm->vmcb->control.exit_info_1 = error_code;
- svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2;
-
- vmexit = nested_svm_intercept(svm);
- if (vmexit == NESTED_EXIT_DONE)
- svm->nested.exit_required = true;
+ if (svm->vcpu.arch.exception.nested_apf)
+ svm->vmcb->control.exit_info_2 = svm->vcpu.arch.apf.nested_apf_token;
+ else
+ svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2;
+ svm->nested.exit_required = true;
return vmexit;
}
@@ -2568,7 +2572,7 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
vmexit = NESTED_EXIT_DONE;
/* async page fault always cause vmexit */
else if ((exit_code == SVM_EXIT_EXCP_BASE + PF_VECTOR) &&
- svm->vcpu.arch.apf.host_apf_reason != 0)
+ svm->vcpu.arch.exception.nested_apf != 0)
vmexit = NESTED_EXIT_DONE;
break;
}
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index d20f794..8724ea6 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2418,13 +2418,24 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
* KVM wants to inject page-faults which it got to the guest. This function
* checks whether in a nested guest, we need to inject them to L1 or L2.
*/
-static int nested_vmx_check_exception(struct kvm_vcpu *vcpu, unsigned nr)
+static int nested_vmx_check_exception(struct kvm_vcpu *vcpu)
{
struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
+ unsigned int nr = vcpu->arch.exception.nr;
- if (!(vmcs12->exception_bitmap & (1u << nr)))
+ if (!((vmcs12->exception_bitmap & (1u << nr)) ||
+ (nr == PF_VECTOR && vcpu->arch.exception.nested_apf)))
return 0;
+ if (vcpu->arch.exception.nested_apf) {
+ vmcs_write32(VM_EXIT_INTR_ERROR_CODE, vcpu->arch.exception.error_code);
+ nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI,
+ PF_VECTOR | INTR_TYPE_HARD_EXCEPTION |
+ INTR_INFO_DELIVER_CODE_MASK | INTR_INFO_VALID_MASK,
+ vcpu->arch.apf.nested_apf_token);
+ return 1;
+ }
+
nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI,
vmcs_read32(VM_EXIT_INTR_INFO),
vmcs_readl(EXIT_QUALIFICATION));
@@ -2441,7 +2452,7 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu)
u32 intr_info = nr | INTR_INFO_VALID_MASK;
if (!reinject && is_guest_mode(vcpu) &&
- nested_vmx_check_exception(vcpu, nr))
+ nested_vmx_check_exception(vcpu))
return;
if (has_error_code) {
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7511c0a..2a4520f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -452,7 +452,12 @@ EXPORT_SYMBOL_GPL(kvm_complete_insn_gp);
void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
{
++vcpu->stat.pf_guest;
- vcpu->arch.cr2 = fault->address;
+ vcpu->arch.exception.nested_apf =
+ is_guest_mode(vcpu) && fault->async_page_fault;
+ if (vcpu->arch.exception.nested_apf)
+ vcpu->arch.apf.nested_apf_token = fault->address;
+ else
+ vcpu->arch.cr2 = fault->address;
kvm_queue_exception_e(vcpu, PF_VECTOR, fault->error_code);
}
EXPORT_SYMBOL_GPL(kvm_inject_page_fault);
@@ -8573,6 +8578,7 @@ void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,
fault.error_code = 0;
fault.nested_page_fault = false;
fault.address = work->arch.token;
+ fault.async_page_fault = true;
kvm_inject_page_fault(vcpu, &fault);
}
}
@@ -8595,6 +8601,7 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
fault.error_code = 0;
fault.nested_page_fault = false;
fault.address = work->arch.token;
+ fault.async_page_fault = true;
kvm_inject_page_fault(vcpu, &fault);
}
vcpu->arch.apf.halted = false;
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH v7 4/4] KVM: async_pf: Let host know whether the guest support delivery async_pf as #PF vmexit
2017-06-29 3:01 [PATCH v7 0/4] KVM: async_pf: Fix async pf exception injection Wanpeng Li
` (2 preceding siblings ...)
2017-06-29 3:02 ` [PATCH v7 3/4] KVM: async_pf: Force a nested vmexit if the injected #PF is async_pf Wanpeng Li
@ 2017-06-29 3:02 ` Wanpeng Li
2017-06-29 7:13 ` [PATCH v7 0/4] KVM: async_pf: Fix async pf exception injection Wanpeng Li
4 siblings, 0 replies; 11+ messages in thread
From: Wanpeng Li @ 2017-06-29 3:02 UTC (permalink / raw)
To: linux-kernel, kvm; +Cc: Paolo Bonzini, Radim Krčmář, Wanpeng Li
From: Wanpeng Li <wanpeng.li@hotmail.com>
Adds another flag bit (bit 2) to MSR_KVM_ASYNC_PF_EN. If bit 2 is 1, async
page faults are delivered to L1 as #PF vmexits; if bit 2 is 0, kvm_can_do_async_pf
returns 0 if in guest mode.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
Documentation/virtual/kvm/msr.txt | 5 +++--
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/include/uapi/asm/kvm_para.h | 1 +
arch/x86/kernel/kvm.c | 7 ++++++-
arch/x86/kvm/mmu.c | 2 +-
arch/x86/kvm/vmx.c | 2 +-
arch/x86/kvm/x86.c | 5 +++--
7 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt
index 0a9ea51..1ebecc1 100644
--- a/Documentation/virtual/kvm/msr.txt
+++ b/Documentation/virtual/kvm/msr.txt
@@ -166,10 +166,11 @@ MSR_KVM_SYSTEM_TIME: 0x12
MSR_KVM_ASYNC_PF_EN: 0x4b564d02
data: Bits 63-6 hold 64-byte aligned physical address of a
64 byte memory area which must be in guest RAM and must be
- zeroed. Bits 5-2 are reserved and should be zero. Bit 0 is 1
+ zeroed. Bits 5-3 are reserved and should be zero. Bit 0 is 1
when asynchronous page faults are enabled on the vcpu 0 when
disabled. Bit 1 is 1 if asynchronous page faults can be injected
- when vcpu is in cpl == 0.
+ when vcpu is in cpl == 0. Bit 2 is 1 if asynchronous page faults
+ are delivered to L1 as #PF vmexits.
First 4 byte of 64 byte memory location will be written to by
the hypervisor at the time of asynchronous page fault (APF)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 71aef4b..a981ab8 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -648,6 +648,7 @@ struct kvm_vcpu_arch {
bool send_user_only;
u32 host_apf_reason;
unsigned long nested_apf_token;
+ bool delivery_as_pf_vmexit;
} apf;
/* OSVW MSRs (AMD only) */
diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
index cff0bb6..a965e5b 100644
--- a/arch/x86/include/uapi/asm/kvm_para.h
+++ b/arch/x86/include/uapi/asm/kvm_para.h
@@ -67,6 +67,7 @@ struct kvm_clock_pairing {
#define KVM_ASYNC_PF_ENABLED (1 << 0)
#define KVM_ASYNC_PF_SEND_ALWAYS (1 << 1)
+#define KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT (1 << 2)
/* Operations for KVM_HC_MMU_OP */
#define KVM_MMU_OP_WRITE_PTE 1
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 43e10d6..71c17a5 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -330,7 +330,12 @@ static void kvm_guest_cpu_init(void)
#ifdef CONFIG_PREEMPT
pa |= KVM_ASYNC_PF_SEND_ALWAYS;
#endif
- wrmsrl(MSR_KVM_ASYNC_PF_EN, pa | KVM_ASYNC_PF_ENABLED);
+ pa |= KVM_ASYNC_PF_ENABLED;
+
+ /* Async page fault support for L1 hypervisor is optional */
+ if (wrmsr_safe(MSR_KVM_ASYNC_PF_EN,
+ (pa | KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT) & 0xffffffff, pa >> 32) < 0)
+ wrmsrl(MSR_KVM_ASYNC_PF_EN, pa);
__this_cpu_write(apf_reason.enabled, 1);
printk(KERN_INFO"KVM setup async PF for cpu %d\n",
smp_processor_id());
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 4a7dc00..fb8c35f 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3705,7 +3705,7 @@ bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu)
kvm_event_needs_reinjection(vcpu)))
return false;
- if (is_guest_mode(vcpu))
+ if (!vcpu->arch.apf.delivery_as_pf_vmexit && is_guest_mode(vcpu))
return false;
return kvm_x86_ops->interrupt_allowed(vcpu);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8724ea6..4f616db 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8001,7 +8001,7 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
if (is_nmi(intr_info))
return false;
else if (is_page_fault(intr_info))
- return enable_ept;
+ return !vmx->vcpu.arch.apf.host_apf_reason && enable_ept;
else if (is_no_device(intr_info) &&
!(vmcs12->guest_cr0 & X86_CR0_TS))
return false;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2a4520f..fdeeb66 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2065,8 +2065,8 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
{
gpa_t gpa = data & ~0x3f;
- /* Bits 2:5 are reserved, Should be zero */
- if (data & 0x3c)
+ /* Bits 3:5 are reserved, Should be zero */
+ if (data & 0x38)
return 1;
vcpu->arch.apf.msr_val = data;
@@ -2082,6 +2082,7 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
return 1;
vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS);
+ vcpu->arch.apf.delivery_as_pf_vmexit = data & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT;
kvm_async_pf_wakeup_all(vcpu);
return 0;
}
--
2.7.4
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH v7 0/4] KVM: async_pf: Fix async pf exception injection
2017-06-29 3:01 [PATCH v7 0/4] KVM: async_pf: Fix async pf exception injection Wanpeng Li
` (3 preceding siblings ...)
2017-06-29 3:02 ` [PATCH v7 4/4] KVM: async_pf: Let host know whether the guest support delivery async_pf as #PF vmexit Wanpeng Li
@ 2017-06-29 7:13 ` Wanpeng Li
2017-06-29 12:15 ` Paolo Bonzini
4 siblings, 1 reply; 11+ messages in thread
From: Wanpeng Li @ 2017-06-29 7:13 UTC (permalink / raw)
To: linux-kernel, kvm; +Cc: Paolo Bonzini, Radim Krčmář, Wanpeng Li
2017-06-29 11:01 GMT+08:00 Wanpeng Li <kernellwp@gmail.com>:
> INFO: task gnome-terminal-:1734 blocked for more than 120 seconds.
> Not tainted 4.12.0-rc4+ #8
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> gnome-terminal- D 0 1734 1015 0x00000000
> Call Trace:
> __schedule+0x3cd/0xb30
> schedule+0x40/0x90
> kvm_async_pf_task_wait+0x1cc/0x270
> ? __vfs_read+0x37/0x150
> ? prepare_to_swait+0x22/0x70
> do_async_page_fault+0x77/0xb0
> ? do_async_page_fault+0x77/0xb0
> async_page_fault+0x28/0x30
>
> This is triggered by running both win7 and win2016 on L1 KVM simultaneously,
> and then gives stress to memory on L1, I can observed this hang on L1 when
> at least ~70% swap area is occupied on L0.
>
> This is due to async pf was injected to L2 which should be injected to L1,
> L2 guest starts receiving pagefault w/ bogus %cr2(apf token from the host
> actually), and L1 guest starts accumulating tasks stuck in D state in
> kvm_async_pf_task_wait() since missing PAGE_READY async_pfs.
>
> This patchset fixes it according to Radim's proposal "force a nested VM exit
> from nested_vmx_check_exception if the injected #PF is async_pf and handle
> the #PF VM exit in L1". https://www.spinics.net/lists/kvm/msg142498.html
Note: The patchset depends on commit d4912215d10 ("KVM: nVMX: Fix
exception injection") and commit 9bc1f09f6fa76fd (KVM: async_pf: avoid
async pf injection when in guest mode) on the master branch.
Regards,
Wanpeng Li
>
> v6 -> v7:
> * drop KVM_GET/PUT_VCPU_EVENTS stuff for nested_apf
>
> v5 -> v6:
> * move vcpu_svm's apf_reason to vcpu->arch.apf.host_apf_reason
> * introduce function kvm_handle_page_fault() to be used by both VMX/SVM
> * introduce svm's codes posted by Paolo
> * introduce nested_apf
> * better set MSR_KVM_ASYNC_PF_EN
>
> v4 -> v5:
> * utilize wrmsr_safe for MSR_KVM_ASYNC_PF_EN
>
> v3 -> v4:
> * reuse pad field in kvm_vcpu_events for async_page_fault
> * update kvm_vcpu_events API documentations
> * change async_page_fault type in vcpu->arch.exception from bool to u8
>
> v2 -> v3:
> * add the flag to the userspace interface(KVM_GET/PUT_VCPU_EVENTS)
>
> v1 -> v2:
> * remove nested_vmx_check_exception nr parameter
> * construct a simple special vm-exit information field for async pf
> * introduce nested_apf_token to vcpu->arch.apf to avoid change the CR2
> visible in L2 guest
> * avoid pass the apf directed towards it (L1) into L2 if there is L3
> at the moment
>
> Wanpeng Li (4):
> KVM: x86: Simple kvm_x86_ops->queue_exception parameter
> KVM: async_pf: Add L1 guest async_pf #PF vmexit handler
> KVM: async_pf: Force a nested vmexit if the injected #PF is async_pf
> KVM: async_pf: Let host know whether the guest support delivery async_pf as #PF vmexit
>
> Documentation/virtual/kvm/msr.txt | 5 ++--
> arch/x86/include/asm/kvm_emulate.h | 1 +
> arch/x86/include/asm/kvm_host.h | 8 +++--
> arch/x86/include/uapi/asm/kvm_para.h | 1 +
> arch/x86/kernel/kvm.c | 7 ++++-
> arch/x86/kvm/mmu.c | 35 +++++++++++++++++++++-
> arch/x86/kvm/mmu.h | 2 ++
> arch/x86/kvm/svm.c | 58 ++++++++++++------------------------
> arch/x86/kvm/vmx.c | 39 +++++++++++++++---------
> arch/x86/kvm/x86.c | 19 +++++++-----
> 10 files changed, 108 insertions(+), 67 deletions(-)
>
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 11+ messages in thread