From: Florian Westphal <fw(a)strlen.de>
[ Upstream commit 1b0890cd60829bd51455dc5ad689ed58c4408227 ]
Thomas and Juliana report a deadlock when running:
(rmmod nf_conntrack_netlink/xfrm_user)
conntrack -e NEW -E &
modprobe -v xfrm_user
They provided following analysis:
conntrack -e NEW -E
netlink_bind()
netlink_lock_table() -> increases "nl_table_users"
nfnetlink_bind()
# does not unlock the table as it's locked by netlink_bind()
__request_module()
call_usermodehelper_exec()
This triggers "modprobe nf_conntrack_netlink" from kernel, netlink_bind()
won't return until modprobe process is done.
"modprobe xfrm_user":
xfrm_user_init()
register_pernet_subsys()
-> grab pernet_ops_rwsem
..
netlink_table_grab()
calls schedule() as "nl_table_users" is non-zero
so modprobe is blocked because netlink_bind() increased
nl_table_users while also holding pernet_ops_rwsem.
"modprobe nf_conntrack_netlink" runs and inits nf_conntrack_netlink:
ctnetlink_init()
register_pernet_subsys()
-> blocks on "pernet_ops_rwsem" thanks to xfrm_user module
both modprobe processes wait on one another -- neither can make
progress.
Switch netlink_bind() to "nowait" modprobe -- this releases the netlink
table lock, which then allows both modprobe instances to complete.
Reported-by: Thomas Jarosch <thomas.jarosch(a)intra2net.com>
Reported-by: Juliana Rodrigueiro <juliana.rodrigueiro(a)intra2net.com>
Signed-off-by: Florian Westphal <fw(a)strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo(a)netfilter.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
net/netfilter/nfnetlink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index 916913454624f..7f2c1915763f8 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -575,7 +575,7 @@ static int nfnetlink_bind(struct net *net, int group)
ss = nfnetlink_get_subsys(type << 8);
rcu_read_unlock();
if (!ss)
- request_module("nfnetlink-subsys-%d", type);
+ request_module_nowait("nfnetlink-subsys-%d", type);
return 0;
}
#endif
--
2.20.1
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From df612421fe2566654047769c6852ffae1a31df16 Mon Sep 17 00:00:00 2001
From: Brian Norris <briannorris(a)chromium.org>
Date: Wed, 24 Jul 2019 12:46:34 -0700
Subject: [PATCH] mwifiex: fix 802.11n/WPA detection
Commit 63d7ef36103d ("mwifiex: Don't abort on small, spec-compliant
vendor IEs") adjusted the ieee_types_vendor_header struct, which
inadvertently messed up the offsets used in
mwifiex_is_wpa_oui_present(). Add that offset back in, mirroring
mwifiex_is_rsn_oui_present().
As it stands, commit 63d7ef36103d breaks compatibility with WPA (not
WPA2) 802.11n networks, since we hit the "info: Disable 11n if AES is
not supported by AP" case in mwifiex_is_network_compatible().
Fixes: 63d7ef36103d ("mwifiex: Don't abort on small, spec-compliant vendor IEs")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Brian Norris <briannorris(a)chromium.org>
Signed-off-by: Kalle Valo <kvalo(a)codeaurora.org>
diff --git a/drivers/net/wireless/marvell/mwifiex/main.h b/drivers/net/wireless/marvell/mwifiex/main.h
index 3e442c7f7882..095837fba300 100644
--- a/drivers/net/wireless/marvell/mwifiex/main.h
+++ b/drivers/net/wireless/marvell/mwifiex/main.h
@@ -124,6 +124,7 @@ enum {
#define MWIFIEX_MAX_TOTAL_SCAN_TIME (MWIFIEX_TIMER_10S - MWIFIEX_TIMER_1S)
+#define WPA_GTK_OUI_OFFSET 2
#define RSN_GTK_OUI_OFFSET 2
#define MWIFIEX_OUI_NOT_PRESENT 0
diff --git a/drivers/net/wireless/marvell/mwifiex/scan.c b/drivers/net/wireless/marvell/mwifiex/scan.c
index 0d6d41727037..21dda385f6c6 100644
--- a/drivers/net/wireless/marvell/mwifiex/scan.c
+++ b/drivers/net/wireless/marvell/mwifiex/scan.c
@@ -181,7 +181,8 @@ mwifiex_is_wpa_oui_present(struct mwifiex_bssdescriptor *bss_desc, u32 cipher)
u8 ret = MWIFIEX_OUI_NOT_PRESENT;
if (has_vendor_hdr(bss_desc->bcn_wpa_ie, WLAN_EID_VENDOR_SPECIFIC)) {
- iebody = (struct ie_body *) bss_desc->bcn_wpa_ie->data;
+ iebody = (struct ie_body *)((u8 *)bss_desc->bcn_wpa_ie->data +
+ WPA_GTK_OUI_OFFSET);
oui = &mwifiex_wpa_oui[cipher][0];
ret = mwifiex_search_oui_in_ie(iebody, oui);
if (ret)
Checking bypass_reg is incorrect for calculating the cnt_clk rates.
Instead we should be checking that there is a proper hardware register
that holds the clock divider.
Cc: stable(a)vger.kernel.org
Signed-off-by: Dinh Nguyen <dinguyen(a)kernel.org>
---
drivers/clk/socfpga/clk-periph-s10.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/clk/socfpga/clk-periph-s10.c b/drivers/clk/socfpga/clk-periph-s10.c
index 5c50e723ecae..1a191eeeebba 100644
--- a/drivers/clk/socfpga/clk-periph-s10.c
+++ b/drivers/clk/socfpga/clk-periph-s10.c
@@ -38,7 +38,7 @@ static unsigned long clk_peri_cnt_clk_recalc_rate(struct clk_hw *hwclk,
if (socfpgaclk->fixed_div) {
div = socfpgaclk->fixed_div;
} else {
- if (!socfpgaclk->bypass_reg)
+ if (socfpgaclk->hw.reg)
div = ((readl(socfpgaclk->hw.reg) & 0x7ff) + 1);
}
--
2.20.0
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 3d584a3c85d6fe2cf878f220d4ad7145e7f89218 Mon Sep 17 00:00:00 2001
From: Anders Roxell <anders.roxell(a)linaro.org>
Date: Fri, 26 Jul 2019 13:27:05 +0200
Subject: [PATCH] arm64: KVM: regmap: Fix unexpected switch fall-through
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
When fall-through warnings was enabled by default, commit d93512ef0f0e
("Makefile: Globally enable fall-through warning"), the following
warnings was starting to show up:
In file included from ../arch/arm64/include/asm/kvm_emulate.h:19,
from ../arch/arm64/kvm/regmap.c:13:
../arch/arm64/kvm/regmap.c: In function ‘vcpu_write_spsr32’:
../arch/arm64/include/asm/kvm_hyp.h:31:3: warning: this statement may fall
through [-Wimplicit-fallthrough=]
asm volatile(ALTERNATIVE(__msr_s(r##nvh, "%x0"), \
^~~
../arch/arm64/include/asm/kvm_hyp.h:46:31: note: in expansion of macro ‘write_sysreg_elx’
#define write_sysreg_el1(v,r) write_sysreg_elx(v, r, _EL1, _EL12)
^~~~~~~~~~~~~~~~
../arch/arm64/kvm/regmap.c:180:3: note: in expansion of macro ‘write_sysreg_el1’
write_sysreg_el1(v, SYS_SPSR);
^~~~~~~~~~~~~~~~
../arch/arm64/kvm/regmap.c:181:2: note: here
case KVM_SPSR_ABT:
^~~~
In file included from ../arch/arm64/include/asm/cputype.h:132,
from ../arch/arm64/include/asm/cache.h:8,
from ../include/linux/cache.h:6,
from ../include/linux/printk.h:9,
from ../include/linux/kernel.h:15,
from ../include/asm-generic/bug.h:18,
from ../arch/arm64/include/asm/bug.h:26,
from ../include/linux/bug.h:5,
from ../include/linux/mmdebug.h:5,
from ../include/linux/mm.h:9,
from ../arch/arm64/kvm/regmap.c:11:
../arch/arm64/include/asm/sysreg.h:837:2: warning: this statement may fall
through [-Wimplicit-fallthrough=]
asm volatile("msr " __stringify(r) ", %x0" \
^~~
../arch/arm64/kvm/regmap.c:182:3: note: in expansion of macro ‘write_sysreg’
write_sysreg(v, spsr_abt);
^~~~~~~~~~~~
../arch/arm64/kvm/regmap.c:183:2: note: here
case KVM_SPSR_UND:
^~~~
Rework to add a 'break;' in the swich-case since it didn't have that,
leading to an interresting set of bugs.
Cc: stable(a)vger.kernel.org # v4.17+
Fixes: a892819560c4 ("KVM: arm64: Prepare to handle deferred save/restore of 32-bit registers")
Signed-off-by: Anders Roxell <anders.roxell(a)linaro.org>
[maz: reworked commit message, fixed stable range]
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
diff --git a/arch/arm64/kvm/regmap.c b/arch/arm64/kvm/regmap.c
index 0d60e4f0af66..a900181e3867 100644
--- a/arch/arm64/kvm/regmap.c
+++ b/arch/arm64/kvm/regmap.c
@@ -178,13 +178,18 @@ void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v)
switch (spsr_idx) {
case KVM_SPSR_SVC:
write_sysreg_el1(v, SYS_SPSR);
+ break;
case KVM_SPSR_ABT:
write_sysreg(v, spsr_abt);
+ break;
case KVM_SPSR_UND:
write_sysreg(v, spsr_und);
+ break;
case KVM_SPSR_IRQ:
write_sysreg(v, spsr_irq);
+ break;
case KVM_SPSR_FIQ:
write_sysreg(v, spsr_fiq);
+ break;
}
}
The patch below does not apply to the 5.2-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 3d584a3c85d6fe2cf878f220d4ad7145e7f89218 Mon Sep 17 00:00:00 2001
From: Anders Roxell <anders.roxell(a)linaro.org>
Date: Fri, 26 Jul 2019 13:27:05 +0200
Subject: [PATCH] arm64: KVM: regmap: Fix unexpected switch fall-through
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
When fall-through warnings was enabled by default, commit d93512ef0f0e
("Makefile: Globally enable fall-through warning"), the following
warnings was starting to show up:
In file included from ../arch/arm64/include/asm/kvm_emulate.h:19,
from ../arch/arm64/kvm/regmap.c:13:
../arch/arm64/kvm/regmap.c: In function ‘vcpu_write_spsr32’:
../arch/arm64/include/asm/kvm_hyp.h:31:3: warning: this statement may fall
through [-Wimplicit-fallthrough=]
asm volatile(ALTERNATIVE(__msr_s(r##nvh, "%x0"), \
^~~
../arch/arm64/include/asm/kvm_hyp.h:46:31: note: in expansion of macro ‘write_sysreg_elx’
#define write_sysreg_el1(v,r) write_sysreg_elx(v, r, _EL1, _EL12)
^~~~~~~~~~~~~~~~
../arch/arm64/kvm/regmap.c:180:3: note: in expansion of macro ‘write_sysreg_el1’
write_sysreg_el1(v, SYS_SPSR);
^~~~~~~~~~~~~~~~
../arch/arm64/kvm/regmap.c:181:2: note: here
case KVM_SPSR_ABT:
^~~~
In file included from ../arch/arm64/include/asm/cputype.h:132,
from ../arch/arm64/include/asm/cache.h:8,
from ../include/linux/cache.h:6,
from ../include/linux/printk.h:9,
from ../include/linux/kernel.h:15,
from ../include/asm-generic/bug.h:18,
from ../arch/arm64/include/asm/bug.h:26,
from ../include/linux/bug.h:5,
from ../include/linux/mmdebug.h:5,
from ../include/linux/mm.h:9,
from ../arch/arm64/kvm/regmap.c:11:
../arch/arm64/include/asm/sysreg.h:837:2: warning: this statement may fall
through [-Wimplicit-fallthrough=]
asm volatile("msr " __stringify(r) ", %x0" \
^~~
../arch/arm64/kvm/regmap.c:182:3: note: in expansion of macro ‘write_sysreg’
write_sysreg(v, spsr_abt);
^~~~~~~~~~~~
../arch/arm64/kvm/regmap.c:183:2: note: here
case KVM_SPSR_UND:
^~~~
Rework to add a 'break;' in the swich-case since it didn't have that,
leading to an interresting set of bugs.
Cc: stable(a)vger.kernel.org # v4.17+
Fixes: a892819560c4 ("KVM: arm64: Prepare to handle deferred save/restore of 32-bit registers")
Signed-off-by: Anders Roxell <anders.roxell(a)linaro.org>
[maz: reworked commit message, fixed stable range]
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
diff --git a/arch/arm64/kvm/regmap.c b/arch/arm64/kvm/regmap.c
index 0d60e4f0af66..a900181e3867 100644
--- a/arch/arm64/kvm/regmap.c
+++ b/arch/arm64/kvm/regmap.c
@@ -178,13 +178,18 @@ void vcpu_write_spsr32(struct kvm_vcpu *vcpu, unsigned long v)
switch (spsr_idx) {
case KVM_SPSR_SVC:
write_sysreg_el1(v, SYS_SPSR);
+ break;
case KVM_SPSR_ABT:
write_sysreg(v, spsr_abt);
+ break;
case KVM_SPSR_UND:
write_sysreg(v, spsr_und);
+ break;
case KVM_SPSR_IRQ:
write_sysreg(v, spsr_irq);
+ break;
case KVM_SPSR_FIQ:
write_sysreg(v, spsr_fiq);
+ break;
}
}
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 5eeaf10eec394b28fad2c58f1f5c3a5da0e87d1c Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz(a)kernel.org>
Date: Fri, 2 Aug 2019 10:28:32 +0100
Subject: [PATCH] KVM: arm/arm64: Sync ICH_VMCR_EL2 back when about to block
Since commit commit 328e56647944 ("KVM: arm/arm64: vgic: Defer
touching GICH_VMCR to vcpu_load/put"), we leave ICH_VMCR_EL2 (or
its GICv2 equivalent) loaded as long as we can, only syncing it
back when we're scheduled out.
There is a small snag with that though: kvm_vgic_vcpu_pending_irq(),
which is indirectly called from kvm_vcpu_check_block(), needs to
evaluate the guest's view of ICC_PMR_EL1. At the point were we
call kvm_vcpu_check_block(), the vcpu is still loaded, and whatever
changes to PMR is not visible in memory until we do a vcpu_put().
Things go really south if the guest does the following:
mov x0, #0 // or any small value masking interrupts
msr ICC_PMR_EL1, x0
[vcpu preempted, then rescheduled, VMCR sampled]
mov x0, #ff // allow all interrupts
msr ICC_PMR_EL1, x0
wfi // traps to EL2, so samping of VMCR
[interrupt arrives just after WFI]
Here, the hypervisor's view of PMR is zero, while the guest has enabled
its interrupts. kvm_vgic_vcpu_pending_irq() will then say that no
interrupts are pending (despite an interrupt being received) and we'll
block for no reason. If the guest doesn't have a periodic interrupt
firing once it has blocked, it will stay there forever.
To avoid this unfortuante situation, let's resync VMCR from
kvm_arch_vcpu_blocking(), ensuring that a following kvm_vcpu_check_block()
will observe the latest value of PMR.
This has been found by booting an arm64 Linux guest with the pseudo NMI
feature, and thus using interrupt priorities to mask interrupts instead
of the usual PSTATE masking.
Cc: stable(a)vger.kernel.org # 4.12
Fixes: 328e56647944 ("KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/put")
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 46bbc949c20a..7a30524a80ee 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -350,6 +350,7 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
void kvm_vgic_load(struct kvm_vcpu *vcpu);
void kvm_vgic_put(struct kvm_vcpu *vcpu);
+void kvm_vgic_vmcr_sync(struct kvm_vcpu *vcpu);
#define irqchip_in_kernel(k) (!!((k)->arch.vgic.in_kernel))
#define vgic_initialized(k) ((k)->arch.vgic.initialized)
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index c704fa696184..482b20256fa8 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -323,6 +323,17 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
{
+ /*
+ * If we're about to block (most likely because we've just hit a
+ * WFI), we need to sync back the state of the GIC CPU interface
+ * so that we have the lastest PMR and group enables. This ensures
+ * that kvm_arch_vcpu_runnable has up-to-date data to decide
+ * whether we have pending interrupts.
+ */
+ preempt_disable();
+ kvm_vgic_vmcr_sync(vcpu);
+ preempt_enable();
+
kvm_vgic_v4_enable_doorbell(vcpu);
}
diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c
index 6dd5ad706c92..96aab77d0471 100644
--- a/virt/kvm/arm/vgic/vgic-v2.c
+++ b/virt/kvm/arm/vgic/vgic-v2.c
@@ -484,10 +484,17 @@ void vgic_v2_load(struct kvm_vcpu *vcpu)
kvm_vgic_global_state.vctrl_base + GICH_APR);
}
-void vgic_v2_put(struct kvm_vcpu *vcpu)
+void vgic_v2_vmcr_sync(struct kvm_vcpu *vcpu)
{
struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
cpu_if->vgic_vmcr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_VMCR);
+}
+
+void vgic_v2_put(struct kvm_vcpu *vcpu)
+{
+ struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
+
+ vgic_v2_vmcr_sync(vcpu);
cpu_if->vgic_apr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_APR);
}
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index c2c9ce009f63..0c653a1e5215 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -662,12 +662,17 @@ void vgic_v3_load(struct kvm_vcpu *vcpu)
__vgic_v3_activate_traps(vcpu);
}
-void vgic_v3_put(struct kvm_vcpu *vcpu)
+void vgic_v3_vmcr_sync(struct kvm_vcpu *vcpu)
{
struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
if (likely(cpu_if->vgic_sre))
cpu_if->vgic_vmcr = kvm_call_hyp_ret(__vgic_v3_read_vmcr);
+}
+
+void vgic_v3_put(struct kvm_vcpu *vcpu)
+{
+ vgic_v3_vmcr_sync(vcpu);
kvm_call_hyp(__vgic_v3_save_aprs, vcpu);
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index 04786c8ec77e..13d4b38a94ec 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -919,6 +919,17 @@ void kvm_vgic_put(struct kvm_vcpu *vcpu)
vgic_v3_put(vcpu);
}
+void kvm_vgic_vmcr_sync(struct kvm_vcpu *vcpu)
+{
+ if (unlikely(!irqchip_in_kernel(vcpu->kvm)))
+ return;
+
+ if (kvm_vgic_global_state.type == VGIC_V2)
+ vgic_v2_vmcr_sync(vcpu);
+ else
+ vgic_v3_vmcr_sync(vcpu);
+}
+
int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 57205beaa981..11adbdac1d56 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -193,6 +193,7 @@ int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address,
void vgic_v2_init_lrs(void);
void vgic_v2_load(struct kvm_vcpu *vcpu);
void vgic_v2_put(struct kvm_vcpu *vcpu);
+void vgic_v2_vmcr_sync(struct kvm_vcpu *vcpu);
void vgic_v2_save_state(struct kvm_vcpu *vcpu);
void vgic_v2_restore_state(struct kvm_vcpu *vcpu);
@@ -223,6 +224,7 @@ bool vgic_v3_check_base(struct kvm *kvm);
void vgic_v3_load(struct kvm_vcpu *vcpu);
void vgic_v3_put(struct kvm_vcpu *vcpu);
+void vgic_v3_vmcr_sync(struct kvm_vcpu *vcpu);
bool vgic_has_its(struct kvm *kvm);
int kvm_vgic_register_its_device(void);
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 5eeaf10eec394b28fad2c58f1f5c3a5da0e87d1c Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz(a)kernel.org>
Date: Fri, 2 Aug 2019 10:28:32 +0100
Subject: [PATCH] KVM: arm/arm64: Sync ICH_VMCR_EL2 back when about to block
Since commit commit 328e56647944 ("KVM: arm/arm64: vgic: Defer
touching GICH_VMCR to vcpu_load/put"), we leave ICH_VMCR_EL2 (or
its GICv2 equivalent) loaded as long as we can, only syncing it
back when we're scheduled out.
There is a small snag with that though: kvm_vgic_vcpu_pending_irq(),
which is indirectly called from kvm_vcpu_check_block(), needs to
evaluate the guest's view of ICC_PMR_EL1. At the point were we
call kvm_vcpu_check_block(), the vcpu is still loaded, and whatever
changes to PMR is not visible in memory until we do a vcpu_put().
Things go really south if the guest does the following:
mov x0, #0 // or any small value masking interrupts
msr ICC_PMR_EL1, x0
[vcpu preempted, then rescheduled, VMCR sampled]
mov x0, #ff // allow all interrupts
msr ICC_PMR_EL1, x0
wfi // traps to EL2, so samping of VMCR
[interrupt arrives just after WFI]
Here, the hypervisor's view of PMR is zero, while the guest has enabled
its interrupts. kvm_vgic_vcpu_pending_irq() will then say that no
interrupts are pending (despite an interrupt being received) and we'll
block for no reason. If the guest doesn't have a periodic interrupt
firing once it has blocked, it will stay there forever.
To avoid this unfortuante situation, let's resync VMCR from
kvm_arch_vcpu_blocking(), ensuring that a following kvm_vcpu_check_block()
will observe the latest value of PMR.
This has been found by booting an arm64 Linux guest with the pseudo NMI
feature, and thus using interrupt priorities to mask interrupts instead
of the usual PSTATE masking.
Cc: stable(a)vger.kernel.org # 4.12
Fixes: 328e56647944 ("KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/put")
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 46bbc949c20a..7a30524a80ee 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -350,6 +350,7 @@ int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
void kvm_vgic_load(struct kvm_vcpu *vcpu);
void kvm_vgic_put(struct kvm_vcpu *vcpu);
+void kvm_vgic_vmcr_sync(struct kvm_vcpu *vcpu);
#define irqchip_in_kernel(k) (!!((k)->arch.vgic.in_kernel))
#define vgic_initialized(k) ((k)->arch.vgic.initialized)
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index c704fa696184..482b20256fa8 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -323,6 +323,17 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
{
+ /*
+ * If we're about to block (most likely because we've just hit a
+ * WFI), we need to sync back the state of the GIC CPU interface
+ * so that we have the lastest PMR and group enables. This ensures
+ * that kvm_arch_vcpu_runnable has up-to-date data to decide
+ * whether we have pending interrupts.
+ */
+ preempt_disable();
+ kvm_vgic_vmcr_sync(vcpu);
+ preempt_enable();
+
kvm_vgic_v4_enable_doorbell(vcpu);
}
diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c
index 6dd5ad706c92..96aab77d0471 100644
--- a/virt/kvm/arm/vgic/vgic-v2.c
+++ b/virt/kvm/arm/vgic/vgic-v2.c
@@ -484,10 +484,17 @@ void vgic_v2_load(struct kvm_vcpu *vcpu)
kvm_vgic_global_state.vctrl_base + GICH_APR);
}
-void vgic_v2_put(struct kvm_vcpu *vcpu)
+void vgic_v2_vmcr_sync(struct kvm_vcpu *vcpu)
{
struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
cpu_if->vgic_vmcr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_VMCR);
+}
+
+void vgic_v2_put(struct kvm_vcpu *vcpu)
+{
+ struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
+
+ vgic_v2_vmcr_sync(vcpu);
cpu_if->vgic_apr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_APR);
}
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index c2c9ce009f63..0c653a1e5215 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -662,12 +662,17 @@ void vgic_v3_load(struct kvm_vcpu *vcpu)
__vgic_v3_activate_traps(vcpu);
}
-void vgic_v3_put(struct kvm_vcpu *vcpu)
+void vgic_v3_vmcr_sync(struct kvm_vcpu *vcpu)
{
struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
if (likely(cpu_if->vgic_sre))
cpu_if->vgic_vmcr = kvm_call_hyp_ret(__vgic_v3_read_vmcr);
+}
+
+void vgic_v3_put(struct kvm_vcpu *vcpu)
+{
+ vgic_v3_vmcr_sync(vcpu);
kvm_call_hyp(__vgic_v3_save_aprs, vcpu);
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index 04786c8ec77e..13d4b38a94ec 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -919,6 +919,17 @@ void kvm_vgic_put(struct kvm_vcpu *vcpu)
vgic_v3_put(vcpu);
}
+void kvm_vgic_vmcr_sync(struct kvm_vcpu *vcpu)
+{
+ if (unlikely(!irqchip_in_kernel(vcpu->kvm)))
+ return;
+
+ if (kvm_vgic_global_state.type == VGIC_V2)
+ vgic_v2_vmcr_sync(vcpu);
+ else
+ vgic_v3_vmcr_sync(vcpu);
+}
+
int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 57205beaa981..11adbdac1d56 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -193,6 +193,7 @@ int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address,
void vgic_v2_init_lrs(void);
void vgic_v2_load(struct kvm_vcpu *vcpu);
void vgic_v2_put(struct kvm_vcpu *vcpu);
+void vgic_v2_vmcr_sync(struct kvm_vcpu *vcpu);
void vgic_v2_save_state(struct kvm_vcpu *vcpu);
void vgic_v2_restore_state(struct kvm_vcpu *vcpu);
@@ -223,6 +224,7 @@ bool vgic_v3_check_base(struct kvm *kvm);
void vgic_v3_load(struct kvm_vcpu *vcpu);
void vgic_v3_put(struct kvm_vcpu *vcpu);
+void vgic_v3_vmcr_sync(struct kvm_vcpu *vcpu);
bool vgic_has_its(struct kvm *kvm);
int kvm_vgic_register_its_device(void);