* [PATCH 1/3] arm64: KVM: fix unmapping with 48-bit VAs
2014-11-21 17:21 [PULL] arm/arm64: KVM: pull request for 3.18-rc6 Marc Zyngier
@ 2014-11-21 17:21 ` Marc Zyngier
2014-11-21 17:21 ` [PATCH 2/3] arm64: KVM: Handle traps of ICC_SRE_EL1 as RAZ/WI Marc Zyngier
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Marc Zyngier @ 2014-11-21 17:21 UTC (permalink / raw)
To: linux-arm-kernel
From: Mark Rutland <mark.rutland@arm.com>
Currently if using a 48-bit VA, tearing down the hyp page tables (which
can happen in the absence of a GICH or GICV resource) results in the
rather nasty splat below, evidently becasue we access a table that
doesn't actually exist.
Commit 38f791a4e499792e (arm64: KVM: Implement 48 VA support for KVM EL2
and Stage-2) added a pgd_none check to __create_hyp_mappings to account
for the additional level of tables, but didn't add a corresponding check
to unmap_range, and this seems to be the source of the problem.
This patch adds the missing pgd_none check, ensuring we don't try to
access tables that don't exist.
Original splat below:
kvm [1]: Using HYP init bounce page @83fe94a000
kvm [1]: Cannot obtain GICH resource
Unable to handle kernel paging request at virtual address ffff7f7fff000000
pgd = ffff800000770000
[ffff7f7fff000000] *pgd=0000000000000000
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 3.18.0-rc2+ #89
task: ffff8003eb500000 ti: ffff8003eb45c000 task.ti: ffff8003eb45c000
PC is at unmap_range+0x120/0x580
LR is at free_hyp_pgds+0xac/0xe4
pc : [<ffff80000009b768>] lr : [<ffff80000009cad8>] pstate: 80000045
sp : ffff8003eb45fbf0
x29: ffff8003eb45fbf0 x28: ffff800000736000
x27: ffff800000735000 x26: ffff7f7fff000000
x25: 0000000040000000 x24: ffff8000006f5000
x23: 0000000000000000 x22: 0000007fffffffff
x21: 0000800000000000 x20: 0000008000000000
x19: 0000000000000000 x18: ffff800000648000
x17: ffff800000537228 x16: 0000000000000000
x15: 000000000000001f x14: 0000000000000000
x13: 0000000000000001 x12: 0000000000000020
x11: 0000000000000062 x10: 0000000000000006
x9 : 0000000000000000 x8 : 0000000000000063
x7 : 0000000000000018 x6 : 00000003ff000000
x5 : ffff800000744188 x4 : 0000000000000001
x3 : 0000000040000000 x2 : ffff800000000000
x1 : 0000007fffffffff x0 : 000000003fffffff
Process swapper/0 (pid: 1, stack limit = 0xffff8003eb45c058)
Stack: (0xffff8003eb45fbf0 to 0xffff8003eb460000)
fbe0: eb45fcb0 ffff8003 0009cad8 ffff8000
fc00: 00000000 00000080 00736140 ffff8000 00736000 ffff8000 00000000 00007c80
fc20: 00000000 00000080 006f5000 ffff8000 00000000 00000080 00743000 ffff8000
fc40: 00735000 ffff8000 006d3030 ffff8000 006fe7b8 ffff8000 00000000 00000080
fc60: ffffffff 0000007f fdac1000 ffff8003 fd94b000 ffff8003 fda47000 ffff8003
fc80: 00502b40 ffff8000 ff000000 ffff7f7f fdec6000 00008003 fdac1630 ffff8003
fca0: eb45fcb0 ffff8003 ffffffff 0000007f eb45fd00 ffff8003 0009b378 ffff8000
fcc0: ffffffea 00000000 006fe000 ffff8000 00736728 ffff8000 00736120 ffff8000
fce0: 00000040 00000000 00743000 ffff8000 006fe7b8 ffff8000 0050cd48 00000000
fd00: eb45fd60 ffff8003 00096070 ffff8000 006f06e0 ffff8000 006f06e0 ffff8000
fd20: fd948b40 ffff8003 0009a320 ffff8000 00000000 00000000 00000000 00000000
fd40: 00000ae0 00000000 006aa25c ffff8000 eb45fd60 ffff8003 0017ca44 00000002
fd60: eb45fdc0 ffff8003 0009a33c ffff8000 006f06e0 ffff8000 006f06e0 ffff8000
fd80: fd948b40 ffff8003 0009a320 ffff8000 00000000 00000000 00735000 ffff8000
fda0: 006d3090 ffff8000 006aa25c ffff8000 00735000 ffff8000 006d3030 ffff8000
fdc0: eb45fdd0 ffff8003 000814c0 ffff8000 eb45fe50 ffff8003 006aaac4 ffff8000
fde0: 006ddd90 ffff8000 00000006 00000000 006d3000 ffff8000 00000095 00000000
fe00: 006a1e90 ffff8000 00735000 ffff8000 006d3000 ffff8000 006aa25c ffff8000
fe20: 00735000 ffff8000 006d3030 ffff8000 eb45fe50 ffff8003 006fac68 ffff8000
fe40: 00000006 00000006 fe293ee6 ffff8003 eb45feb0 ffff8003 004f8ee8 ffff8000
fe60: 004f8ed4 ffff8000 00735000 ffff8000 00000000 00000000 00000000 00000000
fe80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
fea0: 00000000 00000000 00000000 00000000 00000000 00000000 000843d0 ffff8000
fec0: 004f8ed4 ffff8000 00000000 00000000 00000000 00000000 00000000 00000000
fee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
ff00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
ff20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
ff40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
ff60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
ff80: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
ffa0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000005 00000000
ffe0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Call trace:
[<ffff80000009b768>] unmap_range+0x120/0x580
[<ffff80000009cad4>] free_hyp_pgds+0xa8/0xe4
[<ffff80000009b374>] kvm_arch_init+0x268/0x44c
[<ffff80000009606c>] kvm_init+0x24/0x260
[<ffff80000009a338>] arm_init+0x18/0x24
[<ffff8000000814bc>] do_one_initcall+0x88/0x1a0
[<ffff8000006aaac0>] kernel_init_freeable+0x148/0x1e8
[<ffff8000004f8ee4>] kernel_init+0x10/0xd4
Code: 8b000263 92628479 d1000720 eb01001f (f9400340)
---[ end trace 3bc230562e926fa4 ]---
Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jungseok Lee <jungseoklee85@gmail.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm/kvm/mmu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 57a403a..79d3fbf 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -197,7 +197,8 @@ static void unmap_range(struct kvm *kvm, pgd_t *pgdp,
pgd = pgdp + pgd_index(addr);
do {
next = kvm_pgd_addr_end(addr, end);
- unmap_puds(kvm, pgd, addr, next);
+ if (!pgd_none(*pgd))
+ unmap_puds(kvm, pgd, addr, next);
} while (pgd++, addr = next, addr != end);
}
--
2.1.3
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 2/3] arm64: KVM: Handle traps of ICC_SRE_EL1 as RAZ/WI
2014-11-21 17:21 [PULL] arm/arm64: KVM: pull request for 3.18-rc6 Marc Zyngier
2014-11-21 17:21 ` [PATCH 1/3] arm64: KVM: fix unmapping with 48-bit VAs Marc Zyngier
@ 2014-11-21 17:21 ` Marc Zyngier
2014-11-21 17:21 ` [PATCH 3/3] arm/arm64: KVM: vgic: Fix error code in kvm_vgic_create() Marc Zyngier
2014-11-21 18:32 ` [PULL] arm/arm64: KVM: pull request for 3.18-rc6 Paolo Bonzini
3 siblings, 0 replies; 5+ messages in thread
From: Marc Zyngier @ 2014-11-21 17:21 UTC (permalink / raw)
To: linux-arm-kernel
From: Christoffer Dall <christoffer.dall@linaro.org>
When running on a system with a GICv3, we currenly don't allow the guest
to access the system register interface of the GICv3. We do this by
clearing the ICC_SRE_EL2.Enable, which causes all guest accesses to
ICC_SRE_EL1 to trap to EL2 and causes all guest accesses to other ICC_
registers to cause an undefined exception in the guest.
However, we currently don't handle the trap of guest accesses to
ICC_SRE_EL1 and will spill out a warning. The trap just needs to handle
the access as RAZ/WI, and a guest that tries to prod this register and
set ICC_SRE_EL1.SRE=1, must read back the value (which Linux already
does) to see if it succeeded, and will thus observe that ICC_SRE_EL1.SRE
was not set.
Add the simple trap handler in the sorted table of the system registers.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
[ardb: added cp15 handling]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/kvm/sys_regs.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 4cc3b71..3d7c2df 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -424,6 +424,11 @@ static const struct sys_reg_desc sys_reg_descs[] = {
/* VBAR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b0000), Op2(0b000),
NULL, reset_val, VBAR_EL1, 0 },
+
+ /* ICC_SRE_EL1 */
+ { Op0(0b11), Op1(0b000), CRn(0b1100), CRm(0b1100), Op2(0b101),
+ trap_raz_wi },
+
/* CONTEXTIDR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1101), CRm(0b0000), Op2(0b001),
access_vm_reg, reset_val, CONTEXTIDR_EL1, 0 },
@@ -690,6 +695,10 @@ static const struct sys_reg_desc cp15_regs[] = {
{ Op1( 0), CRn(10), CRm( 2), Op2( 1), access_vm_reg, NULL, c10_NMRR },
{ Op1( 0), CRn(10), CRm( 3), Op2( 0), access_vm_reg, NULL, c10_AMAIR0 },
{ Op1( 0), CRn(10), CRm( 3), Op2( 1), access_vm_reg, NULL, c10_AMAIR1 },
+
+ /* ICC_SRE */
+ { Op1( 0), CRn(12), CRm(12), Op2( 5), trap_raz_wi },
+
{ Op1( 0), CRn(13), CRm( 0), Op2( 1), access_vm_reg, NULL, c13_CID },
};
--
2.1.3
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 3/3] arm/arm64: KVM: vgic: Fix error code in kvm_vgic_create()
2014-11-21 17:21 [PULL] arm/arm64: KVM: pull request for 3.18-rc6 Marc Zyngier
2014-11-21 17:21 ` [PATCH 1/3] arm64: KVM: fix unmapping with 48-bit VAs Marc Zyngier
2014-11-21 17:21 ` [PATCH 2/3] arm64: KVM: Handle traps of ICC_SRE_EL1 as RAZ/WI Marc Zyngier
@ 2014-11-21 17:21 ` Marc Zyngier
2014-11-21 18:32 ` [PULL] arm/arm64: KVM: pull request for 3.18-rc6 Paolo Bonzini
3 siblings, 0 replies; 5+ messages in thread
From: Marc Zyngier @ 2014-11-21 17:21 UTC (permalink / raw)
To: linux-arm-kernel
From: Christoffer Dall <christoffer.dall@linaro.org>
If we detect another vCPU is running we just exit and return 0 as if we
succesfully created the VGIC, but the VGIC wouldn't actual be created.
This shouldn't break in-kernel behavior because the kernel will not
observe the failed the attempt to create the VGIC, but userspace could
be rightfully confused.
Cc: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
virt/kvm/arm/vgic.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 3aaca49..aacdb59 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1933,7 +1933,7 @@ out:
int kvm_vgic_create(struct kvm *kvm)
{
- int i, vcpu_lock_idx = -1, ret = 0;
+ int i, vcpu_lock_idx = -1, ret;
struct kvm_vcpu *vcpu;
mutex_lock(&kvm->lock);
@@ -1948,6 +1948,7 @@ int kvm_vgic_create(struct kvm *kvm)
* vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure
* that no other VCPUs are run while we create the vgic.
*/
+ ret = -EBUSY;
kvm_for_each_vcpu(i, vcpu, kvm) {
if (!mutex_trylock(&vcpu->mutex))
goto out_unlock;
@@ -1955,11 +1956,10 @@ int kvm_vgic_create(struct kvm *kvm)
}
kvm_for_each_vcpu(i, vcpu, kvm) {
- if (vcpu->arch.has_run_once) {
- ret = -EBUSY;
+ if (vcpu->arch.has_run_once)
goto out_unlock;
- }
}
+ ret = 0;
spin_lock_init(&kvm->arch.vgic.lock);
kvm->arch.vgic.in_kernel = true;
--
2.1.3
^ permalink raw reply related [flat|nested] 5+ messages in thread