* Re: [PATCH kvmtool] arm64: pvtime: Use correct region size
2022-06-29 10:39 [PATCH kvmtool] arm64: pvtime: Use correct region size Alexandru Elisei
@ 2022-06-29 14:33 ` Andre Przywara
2022-07-01 15:29 ` Sebastian Ene
2022-07-01 15:41 ` Will Deacon
2 siblings, 0 replies; 4+ messages in thread
From: Andre Przywara @ 2022-06-29 14:33 UTC (permalink / raw)
To: Alexandru Elisei
Cc: will, julien.thierry.kdev, maz, linux-arm-kernel, kvmarm,
pierre.gondois, sebastianene
On Wed, 29 Jun 2022 11:39:05 +0100
Alexandru Elisei <alexandru.elisei@arm.com> wrote:
Hi,
> pvtime uses ARM_PVTIME_BASE instead of ARM_PVTIME_SIZE for the size of the
> memory region given to the guest, which causes to the following error when
> creating a flash device (via the -F/--flash command line argument):
>
> Error: RAM (read-only) region [2000000-27fffff] would overlap RAM region [1020000-203ffff]
>
> The read-only region represents the guest memory where the flash image is
> copied by kvmtool. The region starting at 0x102_0000 (ARM_PVTIME_BASE) is
> the pvtime region, which should be 64K in size. kvmtool erroneously creates
> the region to be ARM_PVTIME_BASE in size instead, and the last address
> becomes:
>
> ARM_PVTIME_BASE + ARM_PVTIME_BASE - 1 = 0x102_0000 + 0x102_0000 - 1 = 0x203_ffff
>
> which corresponds to the end of the region from the error message.
>
> Do the right thing and make the pvtime memory region ARM_PVTIME_SIZE = 64K
> bytes, as it was intended.
>
> Fixes: 7d4671e5d372 ("aarch64: Add stolen time support")
> Reported-by: Pierre Gondois <pierre.gondois@arm.com>
> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Oops, this looks indeed like a glaring bug, PVTIME_SIZE was not used
anywhere.
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Cheers,
Andre
> ---
> arm/aarch64/pvtime.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arm/aarch64/pvtime.c b/arm/aarch64/pvtime.c
> index a49cf3ed5478..2933ac7ca959 100644
> --- a/arm/aarch64/pvtime.c
> +++ b/arm/aarch64/pvtime.c
> @@ -14,15 +14,15 @@ static int pvtime__alloc_region(struct kvm *kvm)
> char *mem;
> int ret = 0;
>
> - mem = mmap(NULL, ARM_PVTIME_BASE, PROT_RW,
> + mem = mmap(NULL, ARM_PVTIME_SIZE, PROT_RW,
> MAP_ANON_NORESERVE, -1, 0);
> if (mem == MAP_FAILED)
> return -errno;
>
> ret = kvm__register_ram(kvm, ARM_PVTIME_BASE,
> - ARM_PVTIME_BASE, mem);
> + ARM_PVTIME_SIZE, mem);
> if (ret) {
> - munmap(mem, ARM_PVTIME_BASE);
> + munmap(mem, ARM_PVTIME_SIZE);
> return ret;
> }
>
> @@ -36,8 +36,8 @@ static int pvtime__teardown_region(struct kvm *kvm)
> return 0;
>
> kvm__destroy_mem(kvm, ARM_PVTIME_BASE,
> - ARM_PVTIME_BASE, usr_mem);
> - munmap(usr_mem, ARM_PVTIME_BASE);
> + ARM_PVTIME_SIZE, usr_mem);
> + munmap(usr_mem, ARM_PVTIME_SIZE);
> usr_mem = NULL;
> return 0;
> }
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH kvmtool] arm64: pvtime: Use correct region size
2022-06-29 10:39 [PATCH kvmtool] arm64: pvtime: Use correct region size Alexandru Elisei
2022-06-29 14:33 ` Andre Przywara
@ 2022-07-01 15:29 ` Sebastian Ene
2022-07-01 15:41 ` Will Deacon
2 siblings, 0 replies; 4+ messages in thread
From: Sebastian Ene @ 2022-07-01 15:29 UTC (permalink / raw)
To: Alexandru Elisei
Cc: will, julien.thierry.kdev, maz, linux-arm-kernel, kvmarm,
pierre.gondois
On Wed, Jun 29, 2022 at 11:39:05AM +0100, Alexandru Elisei wrote:
> pvtime uses ARM_PVTIME_BASE instead of ARM_PVTIME_SIZE for the size of the
> memory region given to the guest, which causes to the following error when
> creating a flash device (via the -F/--flash command line argument):
>
> Error: RAM (read-only) region [2000000-27fffff] would overlap RAM region [1020000-203ffff]
>
> The read-only region represents the guest memory where the flash image is
> copied by kvmtool. The region starting at 0x102_0000 (ARM_PVTIME_BASE) is
> the pvtime region, which should be 64K in size. kvmtool erroneously creates
> the region to be ARM_PVTIME_BASE in size instead, and the last address
> becomes:
>
> ARM_PVTIME_BASE + ARM_PVTIME_BASE - 1 = 0x102_0000 + 0x102_0000 - 1 = 0x203_ffff
>
> which corresponds to the end of the region from the error message.
>
> Do the right thing and make the pvtime memory region ARM_PVTIME_SIZE = 64K
> bytes, as it was intended.
>
> Fixes: 7d4671e5d372 ("aarch64: Add stolen time support")
> Reported-by: Pierre Gondois <pierre.gondois@arm.com>
> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
> ---
> arm/aarch64/pvtime.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
Hi,
Thanks for fixing this.
Reviewed-by: Sebastian Ene <sebastianene@google.com>
> diff --git a/arm/aarch64/pvtime.c b/arm/aarch64/pvtime.c
> index a49cf3ed5478..2933ac7ca959 100644
> --- a/arm/aarch64/pvtime.c
> +++ b/arm/aarch64/pvtime.c
> @@ -14,15 +14,15 @@ static int pvtime__alloc_region(struct kvm *kvm)
> char *mem;
> int ret = 0;
>
> - mem = mmap(NULL, ARM_PVTIME_BASE, PROT_RW,
> + mem = mmap(NULL, ARM_PVTIME_SIZE, PROT_RW,
> MAP_ANON_NORESERVE, -1, 0);
> if (mem == MAP_FAILED)
> return -errno;
>
> ret = kvm__register_ram(kvm, ARM_PVTIME_BASE,
> - ARM_PVTIME_BASE, mem);
> + ARM_PVTIME_SIZE, mem);
> if (ret) {
> - munmap(mem, ARM_PVTIME_BASE);
> + munmap(mem, ARM_PVTIME_SIZE);
> return ret;
> }
>
> @@ -36,8 +36,8 @@ static int pvtime__teardown_region(struct kvm *kvm)
> return 0;
>
> kvm__destroy_mem(kvm, ARM_PVTIME_BASE,
> - ARM_PVTIME_BASE, usr_mem);
> - munmap(usr_mem, ARM_PVTIME_BASE);
> + ARM_PVTIME_SIZE, usr_mem);
> + munmap(usr_mem, ARM_PVTIME_SIZE);
> usr_mem = NULL;
> return 0;
> }
> --
> 2.36.1
>
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH kvmtool] arm64: pvtime: Use correct region size
2022-06-29 10:39 [PATCH kvmtool] arm64: pvtime: Use correct region size Alexandru Elisei
2022-06-29 14:33 ` Andre Przywara
2022-07-01 15:29 ` Sebastian Ene
@ 2022-07-01 15:41 ` Will Deacon
2 siblings, 0 replies; 4+ messages in thread
From: Will Deacon @ 2022-07-01 15:41 UTC (permalink / raw)
To: julien.thierry.kdev, andre.przywara, maz, Alexandru Elisei,
sebastianene, pierre.gondois, kvmarm, linux-arm-kernel
Cc: catalin.marinas, kernel-team, Will Deacon
On Wed, 29 Jun 2022 11:39:05 +0100, Alexandru Elisei wrote:
> pvtime uses ARM_PVTIME_BASE instead of ARM_PVTIME_SIZE for the size of the
> memory region given to the guest, which causes to the following error when
> creating a flash device (via the -F/--flash command line argument):
>
> Error: RAM (read-only) region [2000000-27fffff] would overlap RAM region [1020000-203ffff]
>
> The read-only region represents the guest memory where the flash image is
> copied by kvmtool. The region starting at 0x102_0000 (ARM_PVTIME_BASE) is
> the pvtime region, which should be 64K in size. kvmtool erroneously creates
> the region to be ARM_PVTIME_BASE in size instead, and the last address
> becomes:
>
> [...]
Applied to kvmtool (master), thanks!
[1/1] arm64: pvtime: Use correct region size
https://git.kernel.org/will/kvmtool/c/6a1f699108e5
Cheers,
--
Will
https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev
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^ permalink raw reply [flat|nested] 4+ messages in thread