On Wed, 14 Nov 2018 at 14:15, Leif Lindholm <[email protected]> wrote: > > On Wed, Nov 07, 2018 at 02:38:37PM +0100, Ard Biesheuvel wrote: > > On 7 November 2018 at 14:13, Ard Biesheuvel <[email protected]> > > wrote: > > > BaseIoLibIntrinsicArmVirt was created to prevent LTO from merging > > > accesses to MMIO regions, resulting in instructions with multiple > > > output registers that KVM on ARM cannot emulate (since the exception > > > syndrome information that KVM relies on can only describe a single > > > output register) > > > > > > However, using double word loads on ARM amounts to the same thing, > > > and so code that relies on doing 64-bit MMIO to regions that are > > > emulated under KVM (such as the GICv3 TYPER register) will still > > > suffer from the original issue. > > > > > > So replace ldrd and strd with equivalent two instruction sequences. > > > > > > Contributed-under: TianoCore Contribution Agreement 1.1 > > > Signed-off-by: Ard Biesheuvel <[email protected]> > > > > Please consider this patch with the hunk below appended > > Reviewed-by: Leif Lindholm <[email protected]> >
Pushed as 9cabe9d45755fa4e7412e4eba7825d0c46982001 > > > --- > > > MdePkg/Library/BaseIoLibIntrinsic/Arm/ArmVirtMmio.S | 6 ++++-- > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > > > diff --git a/MdePkg/Library/BaseIoLibIntrinsic/Arm/ArmVirtMmio.S > > > b/MdePkg/Library/BaseIoLibIntrinsic/Arm/ArmVirtMmio.S > > > index 3ad22bd5706d..0d802d6928d6 100644 > > > --- a/MdePkg/Library/BaseIoLibIntrinsic/Arm/ArmVirtMmio.S > > > +++ b/MdePkg/Library/BaseIoLibIntrinsic/Arm/ArmVirtMmio.S > > > @@ -125,7 +125,8 @@ ASM_PFX(MmioWrite32Internal): > > > // @return The value read. > > > // > > > ASM_PFX(MmioRead64Internal): > > > - ldrd r0, r1, [r0] > > > + ldr r1, [r0, #4] > > > + ldr r0, [r0] > > > dmb > > > bx lr > > > > > > @@ -141,5 +142,6 @@ ASM_PFX(MmioRead64Internal): > > > // > > > ASM_PFX(MmioWrite64Internal): > > > dmb st > > > - strd r2, r3, [r0] > > > + str r2, [r0] > > > + str r3, [r0, #4] > > > bx lr > > > > diff --git a/MdePkg/Library/BaseIoLibIntrinsic/Arm/ArmVirtMmio.asm > > b/MdePkg/Library/BaseIoLibIntrinsic/Arm/ArmVirtMmio.asm > > index e1a3d68a430c..deba8c1f0c59 100644 > > --- a/MdePkg/Library/BaseIoLibIntrinsic/Arm/ArmVirtMmio.asm > > +++ b/MdePkg/Library/BaseIoLibIntrinsic/Arm/ArmVirtMmio.asm > > @@ -127,7 +127,8 @@ MmioWrite32Internal > > ; @return The value read. > > ; > > MmioRead64Internal > > - ldrd r0, r1, [r0] > > + ldr r1, [r0, #4] > > + ldr r0, [r0] > > dmb > > bx lr > > > > @@ -143,7 +144,8 @@ MmioRead64Internal > > ; > > MmioWrite64Internal > > dmb st > > - strd r2, r3, [r0] > > + str r2, [r0] > > + str r3, [r0, #4] > > bx lr > > > > END _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
