Commit 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro") reorganized el2 setup in such way that virtual cpu id registers set only in nVHE, yet they used (and need) to be set irrespective VHE support. Lack of setup causes 32-bit guest stop booting due to MIDR stay undefined.
Fixes: 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro") Signed-off-by: Vladimir Murzin vladimir.murzin@arm.com ---
There is no upstream fix since issue went away due to code there has been reworked in 5.12: nVHE comes first, so virtual cpu id register are always set.
Maintainers, please, Ack.
arch/arm64/include/asm/el2_setup.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h index f988e94cdf9e..db87daca6b8c 100644 --- a/arch/arm64/include/asm/el2_setup.h +++ b/arch/arm64/include/asm/el2_setup.h @@ -113,7 +113,7 @@ .endm
/* Virtual CPU ID registers */ -.macro __init_el2_nvhe_idregs +.macro __init_el2_idregs mrs x0, midr_el1 mrs x1, mpidr_el1 msr vpidr_el2, x0 @@ -165,6 +165,7 @@ __init_el2_stage2 __init_el2_gicv3 __init_el2_hstr + __init_el2_idregs
/* * When VHE is not in use, early init of EL2 needs to be done here. @@ -173,7 +174,6 @@ * will be done via the _EL1 system register aliases in __cpu_setup. */ .ifeqs "\mode", "nvhe" - __init_el2_nvhe_idregs __init_el2_nvhe_cptr __init_el2_nvhe_sve __init_el2_nvhe_prepare_eret
On Tue, Mar 16, 2021 at 11:25:00AM +0000, Vladimir Murzin wrote:
Commit 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro") reorganized el2 setup in such way that virtual cpu id registers set only in nVHE, yet they used (and need) to be set irrespective VHE support. Lack of setup causes 32-bit guest stop booting due to MIDR stay undefined.
Fixes: 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro") Signed-off-by: Vladimir Murzin vladimir.murzin@arm.com
There is no upstream fix since issue went away due to code there has been reworked in 5.12: nVHE comes first, so virtual cpu id register are always set.
Maintainers, please, Ack.
Why not just use the "rework" patch instead that fixes this issue?
that's always preferred instead of one-off patches.
thanks,
greg k-h
On 3/16/21 11:31 AM, Greg KH wrote:
On Tue, Mar 16, 2021 at 11:25:00AM +0000, Vladimir Murzin wrote:
Commit 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro") reorganized el2 setup in such way that virtual cpu id registers set only in nVHE, yet they used (and need) to be set irrespective VHE support. Lack of setup causes 32-bit guest stop booting due to MIDR stay undefined.
Fixes: 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro") Signed-off-by: Vladimir Murzin vladimir.murzin@arm.com
There is no upstream fix since issue went away due to code there has been reworked in 5.12: nVHE comes first, so virtual cpu id register are always set.
Maintainers, please, Ack.
Why not just use the "rework" patch instead that fixes this issue?>
that's always preferred instead of one-off patches.
That's moderate size patch series [1] which brings new functionality, but more importantly move boot flow upside down, where we first boot nVHE and then switch to VHE if supported. I think that a lot of change to carry in stable compare to proposed fix.
[1] https://lore.kernel.org/kvmarm/20210208095732.3267263-2-maz@kernel.org/
Cheers Vladimir
thanks,
greg k-h
On 2021-03-16 11:31, Greg KH wrote:
On Tue, Mar 16, 2021 at 11:25:00AM +0000, Vladimir Murzin wrote:
Commit 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro") reorganized el2 setup in such way that virtual cpu id registers set only in nVHE, yet they used (and need) to be set irrespective VHE support. Lack of setup causes 32-bit guest stop booting due to MIDR stay undefined.
Fixes: 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro") Signed-off-by: Vladimir Murzin vladimir.murzin@arm.com
There is no upstream fix since issue went away due to code there has been reworked in 5.12: nVHE comes first, so virtual cpu id register are always set.
Maintainers, please, Ack.
Why not just use the "rework" patch instead that fixes this issue?
that's always preferred instead of one-off patches.
It isn't just a "rework" patch. It's a whole series that turns the world upside down, and it really isn't suitable for backporting in the upstream kernel.
My preference would be to fix 5.11. I'll review that patch in a moment.
Thanks,
M.
Hi Vladimir,
On Tue, 16 Mar 2021 11:25:00 +0000, Vladimir Murzin vladimir.murzin@arm.com wrote:
Commit 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro") reorganized el2 setup in such way that virtual cpu id registers set only in nVHE, yet they used (and need) to be set irrespective VHE support. Lack of setup causes 32-bit guest stop booting due to MIDR stay undefined.
Surely this affects 64bit guests as well, doesn't it? I guess the 32bit code tries to infer stuff such as the architecture revision from MIDR and falls over, and that the 64bit Linux code has less baggage?
Fixes: 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro") Signed-off-by: Vladimir Murzin vladimir.murzin@arm.com
There is no upstream fix since issue went away due to code there has been reworked in 5.12: nVHE comes first, so virtual cpu id register are always set.
Maintainers, please, Ack.
arch/arm64/include/asm/el2_setup.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h index f988e94cdf9e..db87daca6b8c 100644 --- a/arch/arm64/include/asm/el2_setup.h +++ b/arch/arm64/include/asm/el2_setup.h @@ -113,7 +113,7 @@ .endm /* Virtual CPU ID registers */ -.macro __init_el2_nvhe_idregs +.macro __init_el2_idregs mrs x0, midr_el1 mrs x1, mpidr_el1 msr vpidr_el2, x0 @@ -165,6 +165,7 @@ __init_el2_stage2 __init_el2_gicv3 __init_el2_hstr
- __init_el2_idregs
/* * When VHE is not in use, early init of EL2 needs to be done here. @@ -173,7 +174,6 @@ * will be done via the _EL1 system register aliases in __cpu_setup. */ .ifeqs "\mode", "nvhe"
- __init_el2_nvhe_idregs __init_el2_nvhe_cptr __init_el2_nvhe_sve __init_el2_nvhe_prepare_eret
The couple of VHE systems I have around don't suffer from this issue, but it looks like I can trigger it on the FVP model (probably because the model is nasty enough to not have VPIDR_EL2 default to anything sensible!).
Anyway, good catch. If you can respin it to drop the reference to 32bit guests, I'll happily ack it!
Thanks,
M.
Hi Marc,
On 3/16/21 1:22 PM, Marc Zyngier wrote:
Hi Vladimir,
On Tue, 16 Mar 2021 11:25:00 +0000, Vladimir Murzin vladimir.murzin@arm.com wrote:
Commit 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro") reorganized el2 setup in such way that virtual cpu id registers set only in nVHE, yet they used (and need) to be set irrespective VHE support. Lack of setup causes 32-bit guest stop booting due to MIDR stay undefined.
Surely this affects 64bit guests as well, doesn't it? I guess the 32bit code tries to infer stuff such as the architecture revision from MIDR and falls over, and that the 64bit Linux code has less baggage?
Correct, that affects all guests, yet 32-bit tries to lookup processor type so it is how it became visible to me
Fixes: 78869f0f0552 ("arm64: Extract parts of el2_setup into a macro") Signed-off-by: Vladimir Murzin vladimir.murzin@arm.com
There is no upstream fix since issue went away due to code there has been reworked in 5.12: nVHE comes first, so virtual cpu id register are always set.
Maintainers, please, Ack.
arch/arm64/include/asm/el2_setup.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h index f988e94cdf9e..db87daca6b8c 100644 --- a/arch/arm64/include/asm/el2_setup.h +++ b/arch/arm64/include/asm/el2_setup.h @@ -113,7 +113,7 @@ .endm /* Virtual CPU ID registers */ -.macro __init_el2_nvhe_idregs +.macro __init_el2_idregs mrs x0, midr_el1 mrs x1, mpidr_el1 msr vpidr_el2, x0 @@ -165,6 +165,7 @@ __init_el2_stage2 __init_el2_gicv3 __init_el2_hstr
- __init_el2_idregs
/* * When VHE is not in use, early init of EL2 needs to be done here. @@ -173,7 +174,6 @@ * will be done via the _EL1 system register aliases in __cpu_setup. */ .ifeqs "\mode", "nvhe"
- __init_el2_nvhe_idregs __init_el2_nvhe_cptr __init_el2_nvhe_sve __init_el2_nvhe_prepare_eret
The couple of VHE systems I have around don't suffer from this issue, but it looks like I can trigger it on the FVP model (probably because the model is nasty enough to not have VPIDR_EL2 default to anything sensible!).
Well firmware could easily hide the issue if it set registers for us ;)
Anyway, good catch. If you can respin it to drop the reference to 32bit guests, I'll happily ack it!
Thanks for prompt review! I'll re-spin it shortly.
Vladimir
Thanks,
M.
linux-stable-mirror@lists.linaro.org
-
Greg KH -
Marc Zyngier -
Vladimir Murzin